An element having electronic configuration 2, 8, 18, 3 belongs to which group of the Modern Periodic Table ?

Options

A. `13^(th)` group
B. `3^(rd)` group
C. `18^(th)` group
D. `15^(th)` group

Explanation

To determine the group of the element with the electronic configuration 2, 8, 18, 3, we will follow these steps:

### Step 1: Understand the Electronic Configuration
The electronic configuration given is 2, 8, 18, 3. This means:
- The first shell (n=1) has 2 electrons.
- The second shell (n=2) has 8 electrons.
- The third shell (n=3) has 18 electrons.
- The fourth shell (n=4) has 3 electrons.

### Step 2: Write the Full Electronic Configuration
We can express the electronic configuration in terms of subshells:
- The first shell (1s) can hold 2 electrons: **1s²**
- The second shell (2s and 2p) can hold 8 electrons: **2s² 2p⁶**
- The third shell (3s, 3p, and 3d) can hold 18 electrons: **3s² 3p⁶ 3d¹⁰**
- The fourth shell (4s and 4p) has 3 electrons: **4s² 4p¹**

So, the complete electronic configuration is:
**1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p¹**

### Step 3: Identify the Last Electron
The last electron in this configuration is in the 4p subshell, specifically in the 4p¹ state.

### Step 4: Determine the Group Number
In the modern periodic table, elements are grouped based on their valence electrons:
- Group 1: ns¹
- Group 2: ns²
- Group 13: ns² np¹
- Group 14: ns² np²
- Group 15: ns² np³
- Group 16: ns² np⁴
- Group 17: ns² np⁵
- Group 18: ns² np⁶

Since the last electron is in the 4p¹ subshell, this element belongs to Group 13 of the periodic table.

### Step 5: Identify the Element
The atomic number corresponding to this electronic configuration is 31, which corresponds to the element Gallium (Ga).

### Conclusion
Therefore, the element with the electronic configuration 2, 8, 18, 3 belongs to **Group 13** of the modern periodic table.

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