Multiple choice

Name the element with the least ionisation potential from the elements of periods 1, 2 and 3.

  1. Hydrogen

  2. Lithium

  3. Sodium

  4. Fluorine

  5. Chlorine

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ionisation potential increases as we move from the left to the right of a period and decreases as we move down a group. Sodium is on the extreme left of period 3. Hence, it has the least ionisation potential as compared to the elements of the first three periods.