In the periodic table from left to right in a period, the atomic volume

Options

A. Increases
B. Decreases
C. Remains constant
D. First increases and then decreases

Answer

To answer the question regarding the atomic volume in the periodic table from left to right in a period, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Atomic Volume**:
Atomic volume is the volume occupied by one mole of an element in its solid state. It can be related to the atomic radius, as atoms can be approximated as spheres.

2. **Movement Across a Period**:
As we move from left to right across a period in the periodic table, the atomic number (number of protons) of the elements increases. This increase in atomic number leads to an increase in the effective nuclear charge (Z_eff) experienced by the outermost electrons.

3. **Effect on Atomic Radius**:
With the increase in effective nuclear charge, the attraction between the nucleus and the outermost electrons becomes stronger. As a result, the electrons are pulled closer to the nucleus, leading to a decrease in atomic radius.

4. **Relating Atomic Radius to Atomic Volume**:
The volume of an atom can be approximated using the formula for the volume of a sphere:
\[ V = \frac{4}{3} \pi r^3 \]
where \( r \) is the atomic radius. Since the atomic radius decreases as we move from left to right, we can infer that the atomic volume will also decrease.

5. **Conclusion**:
Therefore, in the periodic table, as we move from left to right in a period, the atomic volume decreases.

### Final Answer:
In the periodic table, from left to right in a period, the atomic volume decreases.

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