
STAAR Science Grade 8 2016 (tagged to 2021 standards)
Quiz by Grade 8 Science - Texas Education Agency
Track each student's skills and progress in your Mastery dashboards



Element R and Element Q have the same number of valence electrons. These elements both have similar chemical behavior, but Element R has fewer energy levels than Element Q.
Which statement best describes the positions of the two elements in the periodic table?




Lake Victoria in East Africa is home to many species of fish called cichlids. In 1954 the predatory Nile perch was introduced to Lake Victoria. The Nile perch became the dominant fish species in the lake by the mid-1980s. The number of cichlid species in the lake decreased as the Nile perch population increased. The perch preyed heavily on cichlid species that fed on algae and debris on the bottom of the lake. Algae in the lake increased, and oxygen levels decreased. The surface area of the gills of some cichlid species has increased in just over 20 years.
Which statement explains the increase in gill surface area seen in some of Lake Victoria’s cichlids?











The organism in the photo is a daphnia, or water flea. Daphnia are tiny aquatic organisms that live in most freshwater habitats. Adults range from less than 1 to 5 mm in length. They are good swimmers and eat mostly algae. Daphnia become mature at 5 to 10 days, and an adult female can produce up to 100 eggs every 3 or 4 days during its 2-month life span. When harmful algae rapidly increase in the daphnia’s environment, daphnia can develop adaptations to tolerate the negative effects of the algae within 10 years.Â
What characteristic of the daphnia allows the population to adapt to environmental change?

During a lab investigation, students added four 50 g masses to two boxes and arranged the boxes so that they were motionless on a pulley, as shown in the diagram. The students then followed the procedure described in the box. The students recorded their observations after each procedure and reset the pulley system to the original conditions.Â
During which procedures did students observe an unbalanced upward force on Box 1?



A student uses paper and fasteners to create a model of Earth, the sun, and the moon. The sun and Earth are attached to the paper background, while the moon is free to revolve around Earth.Â
Which diagram shows the objects arranged so that a new moon would be visible from Earth?

Students in a science class prepared flash cards so that they could quiz one another about the arrangement of the periodic table. One of the flash cards contained information about two elements, Element L and Element M.Â
The students had to use the information on the flash card to determine possible positions of the two elements on a blank periodic table. Which periodic table has the elements placed in locations that match the information on the flash card?






Nitrogen dioxide is a gas that can be generated by emissions from vehicles and factories. It can also be generated by natural sources, such as forest fires, lightning, and microbial activity in soil. The equation for producing nitrogen dioxide is shown below.Â
Which of these provides evidence that a chemical reaction occurs?









