Write the electronic configuration of element with atomic numbers 89 and 90 and predict whether they are d- or f- block elements .

Explanation

To solve the question about the electronic configuration of elements with atomic numbers 89 and 90, and to determine whether they are d- or f-block elements, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Elements**:
- Atomic number 89 corresponds to the element Actinium (Ac).
- Atomic number 90 corresponds to the element Thorium (Th).

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