Question

Match the atomic number 2, 4, 8, 15 and 19 with each of the following:

1. A solid non-metal belonging to the third period.
2. A metal of valency 1.
3. A gaseous element with valency 2.
4. An element belonging to Group 2.
5. A rare gas.

Answer 1

1. 15
2. 19
3. 8
4. 4
5. 2