Question

what is the valency number of the first 20 elements

Answer 1

Answer:

1 Hydrogen (-1), +1

2 Helium 0

3 Lithium +1

4 Beryllium +2

5 Boron -3, +3

6 Carbon (+2), +4

7 Nitrogen -3, -2, -1, (+1), +2, +3, +4, +5

8 Oxygen -2

9 Fluorine -1, (+1)

10 Neon 0

11 Sodium +1

12 Magnesium +2

13 Aluminum +3

14 Silicon -4, (+2), +4

15 Phosphorus -3, +1, +3, +5

16 Sulfur -2, +2, +4, +6

17 Chlorine -1, +1, (+2), +3, (+4), +5, +7

18 Argon 0

19 Potassium +1

20 Calcium +2