Ionisation energy of sodium is ____________ than that of potassium. (more/less)

Explanation

To determine whether the ionization energy of sodium is more or less than that of potassium, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Elements**: We are comparing sodium (Na) and potassium (K). Both of these elements belong to Group 1 of the periodic table, known as alkali metals.

2. **Understand Ionization Energy**: Ionization energy (IE) is defined as the amount of energy required to remove one electron from the outermost shell of an isolated gaseous atom.

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