Question

can any one help pls​

Answer 1

P=2,8,1

Q=2,8,7

R=2,8,8,1

P and R are in the same group as they have the same number of electrons in the valent shell.so they will have similar property

Answer 2

Electronic configuration:

P - 2,8,1

Q - 2,8,7

R - 2,8,8,1

Here P and R have same number of electrons in their valence shell. Hence, they belong to same group and shows similar properties.