Question
Question: The ionisation energy of alkali metals decreases from Li to Cs because....
The ionisation energy of alkali metals decreases from Li to Cs because.
A
The atomic size increases from Li to Cs
B
The distance between nucleus and outermost orbital decreases from Li to Cs
C
Electropositive character decreases down the group
D
Melting point decreases from Li to Cs.
Answer
The atomic size increases from Li to Cs
Explanation
Solution
: As we move down the group, atomic size increases due to which the distance between the nucleus and the outermost electron increases. Ionisation energy of alkali metals decreases from Li to Cs due to increase in atomic size.