(Blank)
(Blank)
(Blank)
(Blank)
(Blank)
100

H

atomic no 1

100

He

atomic no 2

100

Li

atomic no 3

100

Be

atomic no 4


100

B

atomic no 5


200

C

atomic no 6


200

N

atomic no 7


200

O

atomic no 8


200

F

atomic no 9

200

Ne

atomic no 10

300

Na

atomic no 11

300

Mg

atomic no 12


300

Al

ATOMIC NO 13

300

Ca


ATOMIC NO 14

300

Si

atomic no 15

400

P

atomic no 16

400

S

atomic no 17

400

Cl

atomic no 18

400

Ar

atomic no 19

400

K

atomic no 20