1. A diagram of an atom of lithium is shown.

What is the name of the central part of the atom and which sub-atomic particles does it contain?

Q2-4 Which sub-atomic particle has….

2. ..... a relative mass of one atomic mass unit and no charge?

3. ..... a negative charge?

4. ..... a relative mass of almost zero (1/1836 atomic mass units)?

5. Atoms have no overall charge because the number of ……

• A. protons equals the number of neutrons
• B. protons equals the number of electrons
• C. electrons equals the number of neutrons
• D. protons is less than the number of neutrons

6. The electronic configuration of an atom with 16 electrons is …

• A.  2,8,6
• B.  8,8
• C.  2,6,8
• D.  2,6,6,2

Q7-9 Use the information given in the table below to fill in the missing information for each atom:

10. Information on four particles, W, X, Y and Z is given below. Which are isotopes?

• A.  W and X
• B.  W and Y
• C.   Y and Z
• D.   X and Z