An element has electronic configuration 2, 8,18, 7. Its place in periodic table is in

Options

A. I group
B. II group
C. VII group
D. VIII group

Explanation

To determine the position of the element with the electronic configuration 2, 8, 18, 7 in the periodic table, we can follow these steps:

### Step 1: Identify the number of shells
The electronic configuration is given as 2, 8, 18, 7. This indicates that the element has:
- 2 electrons in the first shell (K)
- 8 electrons in the second shell (L)
- 18 electrons in the third shell (M)
- 7 electrons in the fourth shell (N)

The total number of shells is 4 (K, L, M, N).

**Hint:** Count the number of electron shells based on the given electronic configuration.

### Step 2: Determine the number of valence electrons
The valence electrons are the electrons in the outermost shell. Here, the outermost shell (N) has 7 electrons.

**Hint:** Look at the last shell in the electronic configuration to find the valence electrons.

### Step 3: Identify the group number
In the periodic table, the group number corresponds to the number of valence electrons. Since this element has 7 valence electrons, it belongs to Group 17 (also known as Group VIIA), which consists of the halogens.

**Hint:** The group number can be determined by the number of valence electrons.

### Step 4: Identify the period number
The period number is determined by the number of electron shells. Since there are 4 shells, this element is in the 4th period of the periodic table.

**Hint:** The period number corresponds to the total number of electron shells.

### Step 5: Conclusion
Based on the analysis:
- The element is in Group 17 (due to 7 valence electrons).
- The element is in Period 4 (due to 4 shells).

Thus, the position of the element in the periodic table is in **Group 17 and Period 4**.

**Final Answer:** The element is located in **Group 17, Period 4** of the periodic table.