Question

atomic number of four elements are 5 ,7 ,9 and 10 write-

1) which elements belong to group 18

2) which elements belong to group 15

3) which element belong to group 13

4) which element belong to group 17​

Answer 1

1.5-Boron

2.7-Nitrogen

3.9-fluorine

4.-neon

5.-18 Argon

6.-15 phosphorus

7. -13 Aluminium

8.-17 chlorine