Question

The mass number and Atomic number of an element D are 40 and 18 respectively.
1. What is the group number of D?
2. What is the period number of D?
3. How many valence electrons are there in an atom of D?
4. What is the valency of D?
5. What kind of element is D?
6. The number of protons and neutrons in D is?

Answer 1

1. Group number → 18
2. Period number → 3
3. Valence electrons → 8
4. Valency → 0
5. Type → Noble gas
6. Protons → 18 Neutrons → 22