Question

32. Three elements X, Y, and Z with their atomic numbers are given below:
Element
Atomic Number
Х
16
Y
18
Z
19​

Answer 1

Answer:

M shell means it is third shell ⇒n=3

For element X: atomic number = 18

thus its electronic configuration: 1s

2

2s

2

2p

6

3s

2

3p

6

Electrons in M shell=2+6=8

For element Y: atomic number = 19

thus its electronic configuration: 1s

2

2s

2

2p

6

3s

2

3p

6

4s

1

Electrons in M shell=2+6=8

For element Z: atomic number = 20

thus its electronic configuration: 1s

2

2s

2

2p

6

3s

2

3p

6

4s

2

Electrons in M shell=2+6=8

thus in element X,Y,Z the number of electrons in M shell is 8,8,8 respectively.