Hydrogen resembles with any one of the following
Na, C
alkali metal, halogen
alkali metals, alkaline earth metals
halogen, alkali metals
Name the element which has least ionisation energy
Rb
Cs
F
O2
From the following elements whose atomic numbers are given belong to same period. A = 12, B= 20 , C = 10, D= 15
A and D
A and B
B and D
C and D
Ionisation energy , along the period from left to right
Increase
Decrease
minimized
no change
S is a group member of
O
N
K
Sc
