`A` and `B` belong to same group of periodic table. `A` has higher atomic number than `B`. Which will have lower ionisation energy and why?

Explanation

To determine which element, `A` or `B`, has lower ionization energy, we can follow these steps:

### Step 1: Understand the Position of Elements
- Both `A` and `B` belong to the same group in the periodic table, and `A` has a higher atomic number than `B`. This means that `A` is located below `B` in the same group.

**Hint:** Elements in the same group have similar chemical properties but differ in their atomic size and energy levels.

### Step 2: Analyze Atomic Structure
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