Which one is an example of uninsured cost?

Repair, replacement or damage cost

The MD is worried that they have had 4 loss-time cases in last 12 months. This statement represents which of the following reasons?

3. Human life is very precious and cannot be regain once lost. Right to live safe

2. Sufferings are morally not accepted

1. To protect people from getting killed and suffered from injuries.

The walls of worker restroom are mounted with framed documents including a health and safety management system certificate, the health and safety policy, and public liability insurance. This represents:

Workers' consultation and participation

Element 1.1 (Moral and Money)

SPANISH STUDENTS 10/22/25 In the sentence 'The author chose to juxtapose the wealthy neighborhood with the impoverished area to highlight social inequality,' what does 'juxtapose' most likely mean based on context clues? * 1 point to separate completely to describe in detail to criticize harshly to place side by side for comparison When reading 'This paradox confused everyone: the more he tried to save time, the less time he seemed to have,' what can you infer about a paradox? * 1 point a mathematical equation a simple solution a type of poem a contradictory statement that reveals truth The passage states: 'The author's use of symbolism was evident when the broken mirror represented the character's shattered dreams.' Based on this context, symbolism involves: * 1 point using objects to represent deeper meanings creating rhyming patterns writing in chronological order using literal descriptions only In the text 'Please elaborate on your answer by providing specific examples and detailed explanations,' the word 'elaborate' suggests the need to: * 1 point use simpler words change the topic add more detail make it shorter The critic wrote: 'The actor's performance captured every nuance of emotion, from subtle sadness to barely contained rage.' What does 'nuance' refer to in this context? * 1 point subtle variations in meaning simple emotions loud expressions obvious differences When the text says 'The implication of her silence was clear to everyone in the room, though she never spoke a word,' what does 'implication' mean? * 1 point a command given a direct statement a question asked a conclusion drawn indirectly The scientist stated: 'Based on our limited observations, our hypothesis suggests that plants grow faster with classical music.' What is a hypothesis? * 1 point a type of experiment a proven fact a final conclusion a possible explanation needing more evidence In 'Three witnesses were able to corroborate the defendant's alibi, strengthening his case significantly,' the word 'corroborate' most likely means: * 1 point to question or doubt to confirm or support to change the story to ignore completely The passage reads: 'The student needed to justify her controversial thesis with solid evidence and logical reasoning.' What does 'justify' mean here? * 1 point to make it longer to make excuses for to avoid explaining to prove something is reasonable When the text states 'The researcher was able to synthesize information from five different studies to create a comprehensive theory,' what does 'synthesize' involve? * 1 point copying one source exactly combining multiple sources to create something new rejecting all previous research focusing on only one idea When a reader encounters 'The symbolism in the novel was complex, with the recurring image of doors representing new opportunities throughout the story,' they should: * 1 point memorize all symbols skip symbolic passages look for deeper representational meanings focus only on the literal meaning If a teacher says 'Your essay needs more elaboration - expand on your main points with examples and analysis,' what critical thinking skill is being requested? * 1 point developing ideas with supporting details summarizing briefly using fewer examples changing the topic entirely In the passage 'The dark clouds gathering on the horizon seemed to foreshadow the troubles that would soon befall the village,' what literary technique is being demonstrated? * 1 point The author is using environmental details to hint at future plot developments The author is focusing on realistic weather descriptions The author is using weather to predict actual meteorological events The author is describing a coincidental weather pattern When analyzing 'Sarah knew the antagonist in her favorite novel wasn't just evil—he represented the fear of change that many people experience,' what deeper understanding about antagonists is revealed? * 1 point Antagonists are always completely evil characters Antagonists can represent abstract concepts or human struggles Antagonists must be human characters Antagonists only exist to create action scenes In the sentence 'The protagonist's journey wasn't just about reaching the destination—it was about discovering who she truly was,' what does this suggest about effective protagonists? * 1 point Protagonists must always succeed in their missions Protagonists should remain unchanged throughout the story Protagonists undergo both external and internal development Protagonists should focus only on external goals When the text states 'The word 'home' carried different connotations for each character—warmth and safety for some, confinement and obligation for others,' what critical reading skill is being highlighted? * 1 point Memorizing dictionary definitions Understanding that words have only one correct meaning Identifying grammatical structures Recognizing that word meanings can vary based on personal experience In 'While the denotation of 'snake' is simply a reptile, the author's use of it to describe the character suggests something far more sinister,' what analytical skill is required? * 1 point Understanding reptile biology Memorizing animal classifications Distinguishing between literal and figurative meanings Identifying sentence structure When examining 'The author's tone shifted from hopeful in the opening chapters to increasingly cynical as the story progressed,' what does this reveal about sophisticated writing? * 1 point Tone is unimportant in storytelling Tone changes reflect the author's developing attitude toward the subject Only the ending tone matters Authors should maintain the same tone throughout In analyzing 'The theme of the novel wasn't stated directly but emerged through the characters' repeated struggles with moral choices,' what does this demonstrate about themes? * 1 point Themes develop through patterns in the narrative Themes are only found in the conclusion Themes should always be explicitly stated Themes must be simple moral lessons When the passage reads 'From the character's nervous glances and hesitant speech, readers can infer that she's hiding something important,' what critical thinking process is being described? * 1 point Following explicit plot statements Memorizing character descriptions Making random guesses about character motivations Using textual evidence to draw logical conclusions In 'The ending was deliberately ambiguous, allowing readers to decide whether the character's actions were heroic or selfish,' what does this suggest about sophisticated literature? * 1 point Good stories always have clear, definitive endings Unclear endings indicate poor writing Ambiguity can enhance reader engagement and interpretation Authors should avoid confusing readers When analyzing 'The controversial decision to ban the book sparked debates about censorship versus protecting young readers,' what critical thinking skill is most important? * 1 point Choosing one side immediately Examining multiple perspectives before forming an opinion Avoiding difficult topics entirely Following popular opinion In 'Each character's perspective on the same event revealed how personal experiences shape our understanding of truth,' what deeper concept is being explored? * 1 point All perspectives are equally valid Perspective is unimportant in understanding events There is only one correct way to view any situation Personal background influences how we interpret events When the text states 'The community proved resilient, rebuilding not just their homes but their hope after the disaster,' what does this reveal about the concept of resilience? * 1 point Resilience encompasses both practical and emotional recovery Resilience is an innate trait that cannot be developed Resilience means avoiding all difficulties Resilience only involves physical recovery In analyzing 'The author's portrayal of the character's empathy—her ability to understand her enemy's pain even while fighting him—added complexity to the conflict,' what does this suggest about empathy? * 1 point Empathy means agreeing with everyone Empathy makes people weak in conflicts Empathy should be avoided in difficult situations Empathy can coexist with opposition and create moral complexity When examining 'The character's integrity was tested when telling the truth would hurt people she loved,' what does this reveal about integrity? * 1 point Integrity means always following rules regardless of consequences Integrity means never causing any harm to others Integrity is only important in public situations Integrity involves making difficult moral choices even when costly In 'The student learned to advocate for her ideas by presenting evidence rather than just stating opinions,' what critical skill is being developed? * 1 point Supporting positions with logical reasoning and evidence Avoiding controversial topics entirely Learning to argue loudly and persistently Always agreeing with authority figures If you rewrote a scene from 'The Birchbark House' from Omakayas's grandmother's first-person perspective instead of Omakayas's, how would this most likely change the reader's understanding? * 1 point Nothing would change since they're both female characters The language would become more formal and difficult The story would become less interesting because adults are boring Readers would gain wisdom from experience but lose the innocence of childhood discovery In a plot diagram, the rising action serves which critical purpose beyond simply building toward the climax? * 1 point To provide background information about the setting To confuse readers so the ending is surprising To develop character relationships and establish stakes that make the climax meaningful To make the story longer and more detailed When analyzing the falling action in 'The Birchbark House,' which element would be most important to consider when writing an alternate version? * 1 point Whether the consequences of the climax align with the new direction you want the story to take Making sure it's shorter than the rising action Including a moral lesson for readers How quickly the conflicts get resolved In the exposition of a story, conflict serves which essential function that many readers don't realize? * 1 point To immediately grab attention with action scenes To provide comic relief before serious events To show off the author's writing skills To establish what the characters characterization/personality, which determines what they' must learn to overcome as they face more problems

Use the questions and answers below to make a 10 question quiz: Which principle of interactive media is most impacted by its ‘ubiquity’? A) Restricted access control B) Global market presence and integration C) Limited reach to specific user demographics D) Single-channel broadcasting Answer: B Which feature of interactive media ensures that users can actively control and manipulate the content they access? A) Multimedia integration B) UI simplification C) User interactivity D) System automation Answer: C How does globalisation enhance user experience in interactive media systems, according to 1.1.1? A) By reducing content to a single cultural standard B) By supporting diverse user needs through varied, accessible content C) By enforcing a common global pricing structure D) By allowing one-way communication only Answer: B Why is copyright compliance critical in the context of interactive media? A) It allows users to freely distribute content B) It supports ethical use and protects creators from unauthorized distribution C) It restricts all users from accessing online media D) It focuses solely on preventing duplication of digital games Answer: B In interactive media, 'UX' primarily focuses on what aspect of user engagement? A) Monitoring users’ online activities B) Enabling dynamic user experiences tailored to user intent and satisfaction C) Simplifying multimedia formats to save storage D) Reducing user interaction to maintain control Answer: B What is a key distinction between ‘social issues’ and ‘ethical issues’ in interactive media development? A) Social issues focus on technical concerns, while ethical issues are user-centered B) Social issues relate to user interactions, while ethical issues focus on moral responsibilities C) Social issues address individual rights, whereas ethical issues involve systemic improvements D) Social issues are about compliance, whereas ethical issues concern legal standards Answer: B Which component is crucial to creating an accessible interactive media system for users with disabilities? A) High-end processing units B) Customizable UI elements, such as voice and visual aids C) Limited content based on user demographics D) Exclusive copyright protections Answer: B How does data quality contribute to an interactive media system's success? A) By maximizing data storage for multimedia content B) By ensuring content is relevant, current, and accurate for the intended audience C) By focusing on visual appeal over functionality D) By reducing interaction requirements to enhance performance Answer: B Which factor in interactive media systems enhances global engagement through a seamless user experience? A) Interactivity B) Ubiquity C) Restricted Access D) Content Redundancy Answer: B Why might legal implications arise in interactive media systems despite ethical intentions? A) Compliance with global standards B) Misinterpretations of user intent in a diverse cultural context C) Excessive content validation D) Limited user feedback channels Answer: B

Land warfare is a complex domain that involves the application of military power on the ground to achieve political and strategic objectives. Modern military doctrine, such as that used by the U.S. Army and the Indian Army, categorizes these elements into Combat Power and the Principles of War. 1. The 8 Elements of Combat Power Combat power is the total means of destructive, constructive, and information capabilities that a military unit can apply. It is typically broken down into eight key elements: ElementDescriptionLeadershipThe "multiplier" of all other elements. It provides purpose, direction, and motivation to soldiers.InformationEnables commanders to make informed decisions and creates opportunities to achieve results.Mission CommandThe system used to integrate the other elements. It focuses on decentralized execution based on the commander's intent.Movement & ManeuverThe movement of forces to gain a positional advantage over the enemy to deliver lethal or non-lethal effects.IntelligenceThe understanding of the enemy, terrain, weather, and civil considerations.FiresThe use of weapon systems (artillery, mortars, air support) to create specific lethal or non-lethal effects.SustainmentThe logistics required to maintain operations, including ammunition, fuel, food, and medical support.ProtectionThe preservation of the force so that the commander can apply maximum combat power.2. The Principles of War These are the enduring "rules of thumb" that guide how land forces are employed strategically and tactically: Objective: Direct every operation toward a clearly defined and attainable goal. Offensive: Seize, retain, and exploit the initiative. You cannot win by defending alone. Mass: Concentrate the effects of combat power at the most advantageous place and time. Economy of Force: Allocate the minimum essential combat power to secondary efforts so you can "mass" elsewhere. Maneuver: Place the enemy in a position of disadvantage through flexible movement. Unity of Command: Ensure all forces operate under a single responsible commander toward a common objective. Security: Prevent the enemy from gaining an unexpected advantage. Surprise: Strike the enemy at a time, place, or in a manner for which they are unprepared. Simplicity: Prepare clear, uncomplicated plans to minimize confusion in the "fog of war." 3. The Modern Legal Framework Land warfare is also governed by the Law of Land Warfare (International Humanitarian Law), which rests on four pillars: Military Necessity: Actions must be necessary to achieve a legitimate military goal. Distinction: Forces must distinguish between combatants and non-combatants (civilians). Proportionality: The anticipated harm to civilians must not be excessive in relation to the concrete military advantage gained. Unnecessary Suffering: Weapons and methods must not cause gratuitous or superfluous injury. Note: Contemporary land warfare is increasingly "Multi-Domain," meaning land forces must now integrate with cyber, space, and electronic warfare to be effective. , While land warfare uses many tools, the two primary "philosophies" of how to win a war are Attrition and Maneuver. Most modern conflicts are a spectrum of both, but understanding the pure form of each helps explain military strategy. 1. Attrition Warfare: The "Sledgehammer" Attrition warfare is a strategy where one side attempts to win by wearing down the enemy to the point of collapse through continuous losses in personnel, equipment, and supplies. Core Logic: "I have more than you." It assumes that if you can destroy the enemy’s resources faster than they can replace them, you will eventually win. Focus: Firepower and mass. Success is measured by "body counts," equipment destroyed, and the steady seizing of terrain. Command Style: Usually centralized and methodical. It requires strict synchronization of massive resources (artillery, logistics, manpower). Historical Example: The Battle of Verdun (WWI). German Chief of Staff Erich von Falkenhayn famously stated his goal was to "bleed France white" by forcing them to defend a position they could not afford to lose, regardless of the cost in lives. 2. Maneuver Warfare: The "Scalpel" Maneuver warfare seeks to shatter the enemy’s moral and physical cohesion—their ability to act as a unified force—rather than simply destroying every soldier. Core Logic: "I am faster and more unpredictable than you." It aims to create a state of chaos where the enemy's leadership can no longer make effective decisions. Focus: Speed, surprise, and dislocation (forcing the enemy to be in the wrong place at the wrong time). The OODA Loop: Developed by Col. John Boyd, this is the heart of maneuver theory. It stands for Observe, Orient, Decide, Act. The goal is to cycle through these steps faster than the enemy, essentially "getting inside" their decision-making process until they collapse from confusion. Historical Example: The 1940 Invasion of France (Blitzkrieg). Instead of fighting a line-by-line battle of attrition, German forces used speed and concentrated armor to bypass strongpoints, cut communication lines, and cause a total systemic collapse of the French military in weeks. 3. Key Differences at a Glance FeatureAttrition WarfareManeuver WarfareObjectivePhysical destruction of the enemy army.Functional/Psychological collapse of the enemy.TargetThe enemy's strength (mass).The enemy's weakness (vulnerability).Primary ToolMassed Firepower.Movement and Tempo.Command"Command Push" (Top-down, rigid)."Recon Pull" (Decentralized, flexible).Success MetricExchange ratios (Kill counts).Disruption and loss of enemy control.4. The Modern Synthesis: "Schwerpunkt" In practice, no army is purely "maneuver" or "attrition." To maneuver successfully, you often need a period of attrition to punch a hole in the enemy's line. A critical concept here is the Schwerpunkt (Center of Gravity/Focus of Effort). A commander identifies the single most important place to strike and concentrates all available "elements of power" there. While the rest of the front might look like attrition, the Schwerpunkt is where the maneuver happens to achieve a breakthrough. Modern Reality: In high-intensity conflicts today (like the war in Ukraine), we see a "return to attrition" because modern sensors (drones, satellites) make it very difficult to achieve the surprise needed for pure maneuver warfare. When you can see everything, it's hard to be "unexpected."

1. Laquelle des formes juridiques suivantes offre la meilleure protection du patrimoine personnel de l'entrepreneur ? a) Entreprise individuelle b) Société c) Association de fait d) Aucune de ces réponses 2. Quel est l'inconvénient majeur de l'entreprise individuelle ? a) Difficulté de création b) Régime fiscal complexe c) Responsabilité illimitée de l'entrepreneur d) Impossibilité d'avoir des employés 3. Laquelle des affirmations suivantes concernant la société est vraie ? a) Elle n'a pas d'existence juridique propre. b) Le patrimoine des associés est confondu avec celui de la société. c) Elle peut poursuivre ses activités même après le décès d'un associé. d) Elle est toujours soumise à l'impôt sur le revenu des personnes physiques. 4. Dans une association de fait, que se passe-t-il en cas de mauvaise gestion financière de l'un des associés ? a) Seul l'associé responsable est tenu de rembourser les dettes. b) Tous les associés sont solidairement responsables des dettes. c) L'association est automatiquement dissoute. d) Un tribunal désigne un administrateur judiciaire pour gérer les finances. 5. Lequel des éléments suivants est un avantage de la société par rapport à l'entreprise individuelle ? a) Simplicité de création et de gestion b) Responsabilité limitée des associés c) Contrôle total et décisions unilatérales d) Fiscalité moins avantageuse 6. Qu'est-ce qu'une personne morale ? a) Un individu exerçant une activité commerciale en son nom propre b) Une entité juridique distincte de ses membres, dotée de droits et d'obligations c) Un contrat par lequel deux personnes s'engagent à mettre en commun des biens ou leur travail d) Une forme d'entreprise réservée aux professions libérales 7. Laquelle des affirmations suivantes est vraie concernant l'association de fait ? a) Elle nécessite la création d'une personne morale. b) Elle offre une protection du patrimoine personnel des participants. c) Elle peut être considérée comme une entreprise si elle verse des bénéfices à ses membres. d) Elle est soumise aux mêmes obligations comptables que les sociétés. 8. Quel est l'un des avantages de la société en matière de continuité d'activité ? a) Elle est dissoute automatiquement au décès de son fondateur. b) Elle peut être facilement transmise aux héritiers en cas de décès d'un associé. c) Elle cesse son activité si un associé décide de se retirer. d) Elle doit être liquidée en cas d'incapacité de travail d'un associé. 9. Lequel des critères suivants peut influencer le choix entre une entreprise individuelle et une société ? a) Le montant du capital initial b) Le nombre d'employés c) Le secteur d'activité d) La volonté de protéger son patrimoine personnel 10. Quel est l'un des risques majeurs liés à l'absence de séparation des patrimoines dans l'entreprise individuelle ? a) La responsabilité limitée de l'entrepreneur b) La saisie du patrimoine personnel en cas de dettes de l'entreprise c) L'impossibilité de déduire les charges professionnelles de ses revenus d) La difficulté d'obtenir un financement bancaire

A biografia di Dante, con le notizie dei suoi ascendenti, dei suoi familiari, del suo matrimonio, dei suoi figli, è stata ricostruita da molti autori. Ricordo fra gli altri il piccolo, classico libro di Michele Barbi, che ad oltre ottanta anni di distanza consiglierei ancora per un primo approccio. In queste pochissime pagine mi limiterò a richiamare gli elementi cronologici essenziali, a contestualizzarli nella storia generale e a dire di alcuni momenti della vita di Dante e di alcuni fatti di storia generale rievocati nella Commedia. A tante questioni, vicende e persone, Dante compreso, darò corpo nelle prossime letture. Per adesso uno scheletro. Dante nacque fra il maggio e il giugno del 1265. Un anno che si pone tra la vittoria militare ghibellina di Montaperti (4 settembre 1260) e la vittoria militare guelfa di Colle Val d’Elsa (17 giugno 1269). Dante avrebbe rievocato nella Commedia ambedue questi scontri (Inf. X e Pg. XIII), ancorandoli rispettivamente a un protagonista e ad una osservatrice. L’anno della nascita di Dante è anche un anno cruciale nella storia dell’arte. Nicola Pisano e i suoi aiutanti costruirono nella cattedrale di Siena un pulpito marmoreo che è tra le grandi espressioni di un rinnovamento della cultura artistica; nell’équipe di Nicola era anche Arnolfo di Cambio, altro protagonista di quella strepitosa stagione. Certo non insensibile alle arti figurative ed anche ai momenti di innovazione, come testimoniano alcuni luoghi della Commedia, Dante non disse però nulla dei grandi scultori del Duecento e del primo Trecento. Quando egli era ancora un fanciullo (aveva circa dodici anni) il padre, come era consuetudine, combinò il suo matrimonio. Scelse una donna della consorteria nobiliare dei Donati, Gemma di Manetto, alla quale fu assegnata una dote di 200 lire di fiorini d’oro: somma non piccola ma non strepitosa, della quale Gemma non poté fruire se non tardivamente e in parte, essendo stati sequestrati i beni e i diritti di Dante al momento della condanna all’esilio (1302). Con Gemma Donati Dante ebbe due o forse tre figli maschi e una figlia femmina, persone di una sola delle quali, il figlio Pietro, abbiamo notizie copiose e interessanti. Dante era ancora un bambino quando un grande rivolgimento politico si svolgeva in Italia e Toscana. Dopo la vittoria ghibellina di Montaperti lo schieramento guelfo si riorganizzò, e dal 1269 ottenne una preponderanza in Toscana grazie alla vittoria militare di Colle di Val d’Elsa e soprattutto grazie ad una forte iniziativa dei papi Urbano IV e Clemente IV e all’intervento di Carlo d’Angiò, figlio del re di Francia, vittorioso sui ghibellini a Benevento nel 1266, incoronato re di Sicilia nel 1270 ed aspirante ad una supremazia politica in Italia. Dante sistemerà Carlo d’Angiò e il figlio, re Carlo II, in luoghi diversi del Purgatorio, manifestando nei loro confronti una sostanziale distanza nel giudizio morale (Pg. XX). Esprimerà un giudizio severo su Clemente IV (Pg. III), di Urbano IV non parlerà, e collocherà in Purgatorio il capofila del movimento ghibellino, re Manfredi (Pg. III). Ma nei confronti di Manfredi esprimerà, se non una adesione politica, una forte simpatia umana, ed una umana pietas dedicherà a Corradino, ultimo esponente della casa sveva, fatto giustiziare da Carlo d’Angiò (Pg. XX). Tutto questo “secondo round” del conflitto ghibellino-guelfo, svoltosi tra la morte di Federico II di Svevia (1250) e l’incoronazione di Carlo d’Angiò (1270), vide scenari di grande complessità, e si è accennato come furono complesse, non univoche, le valutazioni che Dante espresse nella Commedia. Complessa fu anche l’evoluzione politica delle città italiane, segnatamente di Firenze. Nel corso degli anni Settanta si andò accentuando la cristallizzazione del conflitto tra nobili e “popolari”, ma si innestò su di esso il problema del contenimento dello strapotere delle grandi famiglie: quei “magnati” o “grandi”, come si dissero, che per tradizione militare e atteggiamento di comando, ricchezza, ampiezza di clientele, potevano avere un ruolo destabilizzante sulla vita civile della città. I ceti dominanti comunali, ampiamente commisti di famiglie nobili e famiglie di mercanti e artigiani, tentarono politiche che da un lato contenessero il contrasto guelfo-ghibellino e da un lato ponessero limiti al potere delle grandi famiglie di ambedue le parti. Tutto questo si concluse in solenni atti di pacificazione tra famiglie e in leggi che vietavano ai potenti l’accesso ad alcune cariche di governo, imponevano ad essi garanzie contro le eventuali offese ai “popolari” e comminavano pene severe in caso di turbamenti dell’ordine pubblico. A Firenze il momento pacificatorio ebbe un suo esito compromissorio e dunque instabile nel 1280 e la legislazione antimagnatizia ebbe un esito altrettanto problematico nel 1293, in ambedue i casi con un ritardo rispetto ad altre realtà comunali dell’Italia centrale quali Siena e Bologna. Nel frattempo, la rivolta siciliana del 1282 (Par. VIII) abbatté il potere di Carlo d’Angiò nell’Italia meridionale, lo intaccò ovunque e vide la contrapposizione all’angioino della casa reale di Aragona, che si volle erede di Manfredi e nuovo sostegno del ghibellinismo. A lungo sarebbero state realtà politiche contrapposte il regno aragonese di Sicilia e il regno angioino di Napoli. Dante avrebbe collocato nel Purgatorio, vicini l’uno all’altro, quei regnanti che in terra erano stati nemici tra loro (Pg. VII), e avrebbe espresso nell’insieme della questione angioino-aragonese giudizi un po’ ambigui. Dobbiamo pensare che ai suoi occhi nessuno di quei sovrani meritasse una supremazia tale da poter rivendicare un ruolo imperiale, l’unico che Dante riteneva veramente importante per le sorti dell’Italia. Mentre si dispiegava quel nuovo scenario degli anni Settanta e Ottanta del Duecento Dante viveva le sue prime esperienze di matrimonio e di paternità, proseguiva e completava una formazione culturale di alto livello, retorica, letteraria e filosofica, e avviava la propria partecipazione alla vita militare, politica e amministrativa della sua città. Questo però non prima della fine degli anni Ottanta. Nel giugno del 1289 (aveva dunque ventiquattro anni) partecipò alla battaglia di Campaldino, scontro tra i guelfi fiorentini e i ghibellini di Arezzo, che avrebbe rievocato nella Commedia (Pg. V). Pochi anni dopo si attuava, come ho accennato, la legislazione antimagnatizia fiorentina per iniziativa di Giano della Bella, che Dante collocherà nel Paradiso con una ampia e complessa valutazione (Par. XVI). Contestuale a questa legislazione “popolare” fu l’obbligo di iscrizione ad una delle Arti per chi volesse partecipare ai Consigli. Nel 1295 Dante si iscrisse all’Arte dei medici e speziali, e dello stesso anno è un suo, forse primo, intervento in uno dei Consigli cittadini. Cinque anni prima era morta una nobile donna, Beatrice, della quale Dante si era innamorato e per la quale sveva scritto, continuando a scrivere dopo la morte di lei, una serie di poesie raccolte in un libro di taglio autobiografico, la Vita nova. Dopo quello del 1295 molti altri interventi di Dante in Consigli diversi sono documentati in questi ultimi cinque anni del Duecento; in alcuni di essi, e poi in una ambasceria al Comune di San Gimignano del maggio 1300, Dante si adoperò per contrastare l’aggressiva e destabilizzante politica attuata in Toscana dal papa Bonifacio VIII, che il poeta dirà atteso in inferno insieme ad altri papi simoniaci (Inf. XIX)(il viaggio della Commedia è immaginato nel 1300, il papa morì nel 1303, così Dante poteva solo anticipare la condanna divina). Nell’aprile del 1301 Dante fu nominato soprastante all’esecuzione di certi lavori pubblici, nello stesso mese e poi ancora nel giugno e nel settembre intervenne in alcuni Consigli. Ho detto nella lettura su Ulisse della modalità scarna secondo la quale erano registrate le delibere, così non ci si deve attendere di leggere un ampio resoconto del discorso pronunziato dal divino poeta; è però abbastanza certo che egli intervenisse per contrastare la politica di Bonifacio VIII e l’intervento del principe francese Carlo di Valois, che il papa aveva fatto intervenire, sotto pretesto pacificatorio, per affermare la propria supremazia in Toscana (di Carlo Dante farà cenno in Pg. XX, canto fondamentale per conoscere l’atteggiamento del poeta verso la casa reale di Francia e i suoi rami). Intorno a queste opzioni politiche si era andata formando una contrapposizione tra un partito filopapale, che si disse dei guelfi Neri, e un opposto gruppo politico ostile alla politica di Bonifacio VIII e Carlo di Valois, che si disse dei Bianchi, nel quale Dante si schierò. La divisione dei Bianchi e dei Neri si era inizialmente definita a Pistoia e fu importata a Firenze, dove trovò i rispettivi capofila in due clan familiari, i Cerchi e i Donati. Poco tempo dopo gli interventi di Dante nei Consigli, nel gennaio 1302, il podestà Cante dei Gabrielli da Gubbio, in seguito all’istruttoria del giudice Paolo da Gubbio, preposto alle questioni di corruzione, ingiuste estorsioni e lucri illeciti, pronunziava la condanna di quattro cittadini, tra i quali Dante, i quali avrebbero commesso quei reati mentre erano nell’ufficio dei priori, il massimo organo di governo comunale. Dante e gli altri imputati si erano nel frattempo allontanati da Firenze, o come nel caso di Dante erano già lontani per diversi motivi, e non si presentarono in un giudizio del quale molto probabilmente presagivano l’esito. Furono pertanto condannati in contumacia (la giustizia dell’epoca riteneva la contumacia equivalente ad una confessione di colpevolezza). La penalità era enorme, 5000 fiorini per ciascuno, e se non fosse stata versata si sarebbe proceduto, come di norma, alla distruzione dei beni dei condannati, per non dire di altre conseguenze (confino, interdizione da uffici eccetera). Nota. Il testo che ho citato in apertura è Michele Barbi, Vita di Dante, Firenze, Sansoni, 1961. Era stato scritto per l’Enciclopedia Italiana, poi fu edito da Sansoni nel 1933 con il titolo Dante. Vita, opere e fortuna. Delle altre biografie ricorderò solo quella di Giorgio Petrocchi, Biografia. Attività politica e letteraria, nell’ Appendice dell’ Enciclopedia dantesca, 1978, pp. 1-53. Fonte documentaria primaria per la biografia di Dante e dei suoi familiari è il Codice diplomatico dantesco, che meriterà un discorso a suo luogo. Autore: Paolo Cammarosano

Covalent Molecules and Compounds Just as an atom is the simplest unit that has the fundamental chemical properties of an element, a molecule is the simplest unit that has the fundamental chemical properties of a covalent compound. Some pure elements exist as covalent molecules. Hydrogen, nitrogen, oxygen, and the halogens occur naturally as the diatomic (“two atoms”) molecules H2, N2, O2, F2, Cl2, Br2, and I2 (part (a) in Figure 3.1.1). Similarly, a few pure elements exist as polyatomic (“many atoms”) molecules, such as elemental phosphorus and sulfur, which occur as P4 and S8 (part (b) in Figure 3.1.1). Each covalent compound is represented by a molecular formula, which gives the atomic symbol for each component element, in a prescribed order, accompanied by a subscript indicating the number of atoms of that element in the molecule. The subscript is written only if the number of atoms is greater than 1. For example, water, with two hydrogen atoms and one oxygen atom per molecule, is written as H2O. Similarly, carbon dioxide, which contains one carbon atom and two oxygen atoms in each molecule, is written as CO2. Covalent compounds that predominantly contain carbon and hydrogen are called organic compounds. The convention for representing the formulas of organic compounds is to write carbon first, followed by hydrogen and then any other elements in alphabetical order (e.g., CH4O is methyl alcohol, a fuel). Compounds that consist primarily of elements other than carbon and hydrogen are called inorganic compounds; they include both covalent and ionic compounds. In inorganic compounds, the component elements are listed beginning with the one farthest to the left in the periodic table, as in CO2 or SF6. Those in the same group are listed beginning with the lower element and working up, as in ClF. By convention, however, when an inorganic compound contains both hydrogen and an element from groups 13–15, hydrogen is usually listed last in the formula. Examples are ammonia (NH3) and silane (SiH4). Compounds such as water, whose compositions were established long before this convention was adopted, are always written with hydrogen first: Water is always written as H2O, not OH2. The conventions for inorganic acids, such as hydrochloric acid (HCl) and sulfuric acid (H2SO4), are described elswhere. Note! For organic compounds: write C first, then H, and then the other elements in alphabetical order. For molecular inorganic compounds: start with the element at far left in the periodic table; list elements in same group beginning with the lower element and working up. Write the molecular formula of each compound. a. The phosphorus-sulfur compound that is responsible for the ignition of so-called strike anywhere matches has 4 phosphorus atoms and 3 sulfur atoms per molecule. b. Ethyl alcohol, the alcohol of alcoholic beverages, has 1 oxygen atom, 2 carbon atoms, and 6 hydrogen atoms per molecule. c. Freon-11, once widely used in automobile air conditioners and implicated in damage to the ozone layer, has 1 carbon atom, 3 chlorine atoms, and 1 fluorine atom per molecule. Solution: a. • A The molecule has 4 phosphorus atoms and 3 sulfur atoms. Because the compound does not contain mostly carbon and hydrogen, it is inorganic. • B Phosphorus is in group 15, and sulfur is in group 16. Because phosphorus is to the left of sulfur, it is written first. • C Writing the number of each kind of atom as a right-hand subscript gives P4S3 as the molecular formula. b. • A Ethyl alcohol contains predominantly carbon and hydrogen, so it is an organic compound. • B The formula for an organic compound is written with the number of carbon atoms first, the number of hydrogen atoms next, and the other atoms in alphabetical order: CHO. • C Adding subscripts gives the molecular formula C2H6O. c. • A Freon-11 contains carbon, chlorine, and fluorine. It can be viewed as either an inorganic compound or an organic compound (in which fluorine has replaced hydrogen). The formula for Freon-11 can therefore be written using either of the two conventions. • B According to the convention for inorganic compounds, carbon is written first because it is farther left in the periodic table. Fluorine and chlorine are in the same group, so they are listed beginning with the lower element and working up: CClF. Adding subscripts gives the molecular formula CCl3F. • C We obtain the same formula for Freon-11 using the convention for organic compounds. The number of carbon atoms is written first, followed by the number of hydrogen atoms (zero) and then the other elements in alphabetical order, also giving CCl3F. Write the molecular formula for each compound. a. Nitrous oxide, also called “laughing gas,” has 2 nitrogen atoms and 1 oxygen atom per molecule. Nitrous oxide is used as a mild anesthetic for minor surgery and as the propellant in cans of whipped cream. b. Sucrose, also known as cane sugar, has 12 carbon atoms, 11 oxygen atoms, and 22 hydrogen atoms. c. Sulfur hexafluoride, a gas used to pressurize “unpressurized” tennis balls and as a coolant in nuclear reactors, has 6 fluorine atoms and 1 sulfur atom per molecule. Answer: a. N2O b. C12H22O11 c. SF6. Ionic Compounds The substances described in the preceding discussion are composed of molecules that are electrically neutral; that is, the number of positively-charged protons in the nucleus is equal to the number of negatively-charged electrons. In contrast, ions are atoms or assemblies of atoms that have a net electrical charge. Ions that contain fewer electrons than protons have a net positive charge and are called cations. Conversely, ions that contain more electrons than protons have a net negative charge and are called anions. Ionic compounds contain both cations and anions in a ratio that results in no net electrical charge. Note! Ionic compounds contain both cations and anions in a ratio that results in zero electrical charge.An ionic compound that contains only two elements, one present as a cation and one as an anion, is called a binary ionic compound. One example is MgCl2, a coagulant used in the preparation of tofu from soybeans. For binary ionic compounds, the subscripts in the empirical formula can also be obtained by crossing charges: use the absolute value of the charge on one ion as the subscript for the other ion. This method is shown schematically as follows: Crossing charges. One method for obtaining subscripts in the empirical formula is by crossing charges. When crossing charges, it is sometimes necessary to reduce the subscripts to their simplest ratio to write the empirical formula. Consider, for example, the compound formed by Mg2+ and O2−. Using the absolute values of the charges on the ions as subscripts gives the formula Mg2O2:Polyatomic Ions Polyatomic ions are groups of atoms that bear net electrical charges, although the atoms in a polyatomic ion are held together by the same covalent bonds that hold atoms together in molecules. Just as there are many more kinds of molecules than simple elements, there are many more kinds of polyatomic ions than monatomic ions. Two examples of polyatomic cations are the ammonium (NH4+) and the methylammonium (CH3NH3+) ions. P. The method used to predict the empirical formulas for ionic compounds that contain monatomic ions can also be used for compounds that contain polyatomic ions. The overall charge on the cations must balance the overall charge on the anions in the formula unit. Thus, K+ and NO3− ions combine in a 1:1 ratio to form KNO3 (potassium nitrate or saltpeter), a major ingredient in black gunpowder. Similarly, Ca2+ and SO42− form CaSO4 (calcium sulfate), which combines with varying amounts of water to form gypsum and plaster of Paris. The polyatomic ions NH4+ and NO3− form NH4NO3 (ammonium nitrate), a widely used fertilizer and, in the wrong hands, an explosive. One example of a compound in which the ions have charges of different magnitudes is calcium phosphate, which is composed of Ca2+ and PO43− ions; it is a major component of bones. The compound is electrically neutral because the ions combine in a ratio of three Ca2+ ions [3(+2) = +6] for every two ions [2(−3) = −6], giving an empirical formula of Ca3(PO4)2; the parentheses around PO4 in the empirical formula indicate that it is a polyatomic ion. Writing the formula for calcium phosphate as Ca3P2O8 gives the correct number of each atom in the formula unit, but it obscures the fact that the compound contains readily identifiable PO43− ions.Summary • There are two fundamentally different kinds of chemical bonds (covalent and ionic) that cause substances to have very different properties. • The composition of a compound is represented by an empirical or molecular formula, each consisting of at least one formula unit.Contributors The atoms in chemical compounds are held together by attractive electrostatic interactions known as chemical bonds. Ionic compounds contain positively and negatively charged ions in a ratio that results in an overall charge of zero. The ions are held together in a regular spatial arrangement by electrostatic forces. Most covalent compounds consist of molecules, groups of atoms in which one or more pairs of electrons are shared by at least two atoms to form a covalent bond. The atoms in molecules are held together by the electrostatic attraction between the positively charged nuclei of the bonded atoms and the negatively charged electrons shared by the nuclei. The molecular formula of a covalent compound gives the types and numbers of atoms present. Compounds that contain predominantly carbon and hydrogen are called organic compounds, whereas compounds that consist primarily of elements other than carbon and hydrogen are inorganic compounds. Diatomic molecules contain two atoms, and polyatomic molecules contain more than two. A structural formula indicates the composition and approximate structure and shape of a molecule. Single bonds, double bonds, and triple bonds are covalent bonds in which one, two, and three pairs of electrons, respectively, are shared between two bonded atoms. Atoms or groups of atoms that possess a net electrical charge are called ions; they can have either a positive charge (cations) or a negative charge (anions). Ions can consist of one atom (monatomic ions) or several (polyatomic ions). The charges on monatomic ions of most main group elements can be predicted from the location of the element in the periodic table. Ionic compounds usually form hard crystalline solids with high melting points. Covalent molecular compounds, in contrast, consist of discrete molecules held together by weak intermolecular forces and can be gases, liquids, or solids at room temperature and pressure. An empirical formula gives the relative numbers of atoms of the elements in a compound, reduced to the lowest whole numbers. The formula unit is the absolute grouping represented by the empirical formula of a compound, either ionic or covalent. Empirical formulas are particularly useful for describing the composition of ionic compounds, which do not contain readily identifiable molecules. Some ionic compounds occur as hydrates, which contain specific ratios of loosely bound water molecules called waters of hydration.

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