The electronic configuration of three elements X, Y and Z is given below: X = 2 Y=2,6 Z=2,8, 2
Which element belongs to the second period ?

Options

A. X
B. Y
C. Z
D. none of these

Explanation

To determine which element belongs to the second period based on their electronic configurations, let's analyze the given configurations step by step.

### Step 1: Identify the electronic configurations
We have the following electronic configurations:
- Element X: 2
- Element Y: 2, 6
- Element Z: 2, 8, 2

### Step 2: Determine the atomic numbers
The atomic number corresponds to the total number of electrons in a neutral atom. Thus:
- For Element X: The configuration 2 indicates it has 2 electrons, which corresponds to atomic number 2 (Helium).
- For Element Y: The configuration 2, 6 indicates it has a total of 2 + 6 = 8 electrons, which corresponds to atomic number 8 (Oxygen).
- For Element Z: The configuration 2, 8, 2 indicates it has a total of 2 + 8 + 2 = 12 electrons, which corresponds to atomic number 12 (Magnesium).

### Step 3: Identify the periods of the elements
To find out which period these elements belong to, we can refer to the periodic table:
- The first period contains elements with atomic numbers 1 and 2 (Hydrogen and Helium).
- The second period contains elements with atomic numbers 3 to 10 (Lithium to Neon).
- The third period contains elements with atomic numbers 11 to 18 (Sodium to Argon).

From the atomic numbers we found:
- Element X (atomic number 2) is in the **first period**.
- Element Y (atomic number 8) is in the **second period**.
- Element Z (atomic number 12) is in the **third period**.

### Conclusion
Thus, the element that belongs to the second period is **Element Y**.

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