Multiple choice

Which of the following elements would lose an electron easily?

Ionisation energy is the energy required to remove the most loosely held electron from one mole of gas. This is more easily seen in symbol terms as

 X(g)------------->X+ + e-

  1. 11Na23

  2. 12Mg24

  3. 19K37

  4. 20Ca40

  5. 56Ba137

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

First ionisation energy of potassium is 419 kJmol-1.