Question

salt (nacl), water (h₂o), and carbon dioxide (co₂) are examples of which of the following?
a atoms
b elements
c compounds
d all of the above

Explanation:

• Atoms are the basic units of matter. For example, a sodium atom (\(Na\)) or a chlorine atom (\(Cl\)). But \(NaCl\), \(H_2O\), and \(CO_2\) are not single atoms.
• Elements are pure substances made of only one type of atom. For example, oxygen (\(O_2\)) is an element (composed of oxygen atoms). But \(NaCl\) (made of sodium and chlorine), \(H_2O\) (made of hydrogen and oxygen), and \(CO_2\) (made of carbon and oxygen) are not single - element substances.
• Compounds are substances formed when two or more different elements chemically combine in a fixed ratio. \(NaCl\) is formed by sodium (\(Na\)) and chlorine (\(Cl\)), \(H_2O\) by hydrogen (\(H\)) and oxygen (\(O\)), and \(CO_2\) by carbon (\(C\)) and oxygen (\(O\)).

Answer:

C. compounds