The density of alkali metals increases from Li to Cs.

Explanation

To analyze the statement that the density of alkali metals increases from lithium (Li) to cesium (Cs), we can break down the reasoning into several steps:

### Step-by-Step Solution:

1. **Identify the Alkali Metals**:
- The alkali metals are found in Group 1 of the periodic table and include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), and cesium (Cs).

2. **Understand the Trend in Atomic Size**:
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