Question

write down the characteristics of the element having atomic number 20​

Answer 1

Step-by-step explanation:

Chlorine has atomic number 17.

Electronic Configuration- 1s

2

2s

2

2p

6

3s

2

3p

5

.

Period Number-3

Group number- VII (A) or 17

Element Family- Halogens

No. of valence electrons- 7

Valency- 1

Metal/ Non-metal- Non-metal.