Among the following Ca ,Mg, P and CI the order of increasing atomic radius is

Options

A. `Cl lt P lt Mg lt Ca`
B. `P lt Cl lt Ca lt Mg`
C. `Ca lt Mg lt P lt Cl`
D. `Mg lt Ca lt Cl lt P`

Answer

To determine the order of increasing atomic radius among the elements Ca (Calcium), Mg (Magnesium), P (Phosphorus), and Cl (Chlorine), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Periodic Table Position**:
- Calcium (Ca) is in Group 2 and Period 4.
- Magnesium (Mg) is in Group 2 and Period 3.
- Phosphorus (P) is in Group 15 and Period 3.
- Chlorine (Cl) is in Group 17 and Period 3.

2. **Understand Atomic Radius Trends**:
- Atomic radius increases down a group due to the addition of electron shells.
- Atomic radius decreases across a period from left to right due to increased effective nuclear charge, which pulls electrons closer to the nucleus.

3. **Compare Atomic Radii in the Same Period**:
- In Period 3 (Mg, P, Cl):
- Mg (Group 2) has a larger atomic radius than P (Group 15) and Cl (Group 17) because it is to the left.
- P has a larger atomic radius than Cl because it is to the left of Cl.

4. **Compare Atomic Radii Across Periods**:
- Ca (Period 4) will have a larger atomic radius than Mg (Period 3) because it is in a lower period.

5. **Establish the Order**:
- From the comparisons:
- Cl < P < Mg < Ca
- Therefore, the order of increasing atomic radius is:
- Cl < P < Mg < Ca

### Final Answer:
The order of increasing atomic radius is: **Cl < P < Mg < Ca**.