Question
Chemistry Question on trends in periodic table
Which of the following has lowest first ionization energy?
A
H
B
He
C
Xe
D
Li
Answer
Li
Explanation
Solution
Ionisation energy increases as we move left to right across a period (i.e., from Li to Ne) and decreases when from top to bottom in a group. Hence, ionisation energy of lithium (Li) is lowest in the given elements.