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

Options

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

Answer

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

### Step 1: Identify the Position of Elements in the Periodic Table
- Calcium (Ca) and Magnesium (Mg) are in Group 2 (alkaline earth metals).
- Phosphorus (P) is in Group 15 (non-metals).
- Chlorine (Cl) is in Group 17 (halogens).

### Step 2: Understand the Trend of Atomic Radius
- Atomic radius decreases as you move from left to right across a period due to an increase in effective nuclear charge, which pulls the electrons closer to the nucleus.
- Atomic radius increases as you move down a group due to the addition of electron shells.

### Step 3: Compare Atomic Radii
- Between Magnesium (Mg) and Calcium (Ca), Calcium is below Magnesium in the same group, so Calcium has a larger atomic radius than Magnesium.
- Between Magnesium (Mg), Phosphorus (P), and Chlorine (Cl), we know that:
- Magnesium (Group 2) is to the left of Phosphorus (Group 15) and Chlorine (Group 17), so it has a larger atomic radius than both.
- Phosphorus is to the left of Chlorine, so Phosphorus has a larger atomic radius than Chlorine.

### Step 4: Establish the Order of Increasing Atomic Radius
From the comparisons:
- Cl < P < Mg < Ca

Thus, the order of increasing atomic radius is:
**Cl < P < Mg < Ca**

### Final Answer
The correct order of increasing atomic radius among Ca, Mg, P, and Cl is:
**Chlorine (Cl) < Phosphorus (P) < Magnesium (Mg) < Calcium (Ca)**