The basicity of hydroxides of lanthanides ........... with increase in atomic member due to ............... .

Explanation

To answer the question regarding the basicity of hydroxides of lanthanides, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding Basicity**: Basicity refers to the ability of a compound to accept protons (H⁺ ions) or donate electron pairs. In the context of hydroxides, it indicates how well the hydroxide can react with acids.

2. **Lanthanides Overview**: The lanthanides are a series of 15 chemical elements from lanthanum (La) to lutetium (Lu) in the periodic table. They are known for their similar properties and are often studied together.

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