Atoms and molecules medium

Atoms and Molecules Quiz (Medium)

1. An atom of an element is identified by its:

a) Atomic mass b) Atomic number c) Valency d) Mass number

2. The particles that take part in a chemical reaction are:

a) Electrons only b) Protons only c) Electrons and protons d) Atoms and molecules

3. The chemical formula C6H12O6 represents:

a) Glucose b) Water c) Carbon dioxide d) Methane

4. The relative atomic mass of an element is measured in:

a) Grams b) Atomic mass units (amu) c) Moles d) Liters

5. The chemical formula HCl represents:

a) Hydrochloric acid b) Hydrogen chloride c) Helium chloride d) Hydrogen carbonate

6. The number of oxygen atoms in one molecule of carbon dioxide (CO2) is:

a) 1 b) 2 c) 3 d) 4

7. The chemical formula of water is:

a) H2O b) H2O2 c) HO2 d) H3O+

8. The atomicity of ozone (O3) is:

a) Monoatomic b) Diatomic c) Triatomic d) Tetraatomic

9. The molecular formula of methane is:

a) CH2 b) CH3 c) C2H6 d) C3H8

10. The sum of the atomic masses of all the atoms in a molecule is called:

a) Atomic mass b) Molecular mass c) Molar mass d) Avogadro's number