1. The atomic number of an element will tell you the number of present in the atom's nucleus.

2. If a chlorine atom has an atomic number of 17 how many protons and electrons does it have?

a) 17
b) 34
c) 35
d) 37.5

3. The mass number of an atom is the sum of the number of positively charged and the number of present in the nucleus.

4. What are isotopes?

a) Atoms with the same number of electrons but different numbers of protons
b) Atoms with the same number of protons but different numbers of neutrons in the nucleus
c) Atoms with the same mass number but different atomic numbers
d) Atoms with similar chemical properties

5. Which sub-atomic particle determines the chemical properties of an element?

a) Neutron
b) Proton
c) Electron
d) Nucleus

6. Why do isotopes of the same element have identical chemical properties?

a) They have the same number of neutrons
b) They have the same number of protons
c) They have the same number of electrons
d) They have the same relative atomic masses

7. What does the term abundance mean when used in reference to isotopes?

a) How common that particular isotope of the element is
b) How reactive one particular isotope is when compared to other isotopes of the same element

8. How is the relative atomic mass of an element calculated?

a) By adding together all the mass numbers of each isotope of the element
b) By averaging the mass numbers of all the isotopes of that particular element
c) By simply using the mass number of the most common isotope
d) By taking the weighted average of the isotopes mass numbers taking ino account the abundance of each isotope

9. Tritium is an isotope of the element hydrogen; it has 1 proton and 2 neutrons in its nucleus and 1 electron in the electron shells. What is the mass number of tritium?

a) 1
b) 2
c) 3
d) 3.5

10. Which of the following statements is true about tritium?

a) Tritium will react in an identical way to other isotopes of hydrogen
b) Tritium will react differently from the other isotopes of hydrogen
c) Tritium is the most reactive isotope of hydrogen
d) Tritium is the least reactive isotope of hydrogen