Question

write down the periodic table 1 to 20. please help me...

Answer 1

1 hydrogen
2 helium
3 lithium
4 berilium
5 boron
6 carbon
7 nitrogen
8 oxygen
9 fluorine
10 neon
11 sodium
12 magnesium
13 aluminium
14 silicon
15 phosphorus
16 sulphur
17 clorine
18 argon
19 potassium
20 calcium