Question

name the elements in the correct order of their increasing atomic number present in the first, second and third short periods of the periodic table​

Answer 1

Helium
Hydrogen
Lithium
Beryllium
Boron
Carbon
.....

Hope this helps.

Answer 2

Answer:

First periodic contains 2 elements (hydrogen and helium) which has atomic numbers 1 and 2 respectively.

Second periodic contains 8 elements (Li, Be, B, C, N, O, F, Ne) which has atomic numbers 3,4,5,6,7 and 8 respectively.

Third periodic contains 8 elements (Na, Mg, Al, Si, P, S, Cl, Ar) which has atomic numbers 9,10,11,12,13,14,15 and respectively.