Which of these determines the identity of an element?

Sodium is an element found in table salt. It contains 11 protons and 12 neutrons. How many electrons are found in a neutral atom of sodium?

What is formed when two or more elements are chemically combined?

Elements are described as pure substances because

The nucleus of an atom contains

How are the elements in the modern periodic table arranged?

Which elements in the periodic table are least likely to combine with other elements?

Carbon and oxygen combine chemically to form carbon dioxide. Carbon dioxide is

Which of these is not made up of two or more substances that are combined physically?

Filtration can be used to separate a mixture of

Which of these processes would be useful for separating a dissolved solid from a liquid?

Which of the following statements about elements is false?

Which term describes the substance that forms when two or more types of atoms join?