Which element has twice as many electrons in its second shell as in the first shell?

Options

A. Be
B. B
C. C
D. N

Explanation

To determine which element has twice as many electrons in its second shell as in the first shell, we can follow these steps:

### Step 1: Understand Electron Shells
- The electron configuration of an atom is organized into shells. The first shell (K shell) can hold a maximum of 2 electrons, while the second shell (L shell) can hold up to 8 electrons.

### Step 2: Set Up the Relationship
- According to the question, we need to find an element where the number of electrons in the second shell (L shell) is twice that in the first shell (K shell). This means if the first shell has \( x \) electrons, the second shell must have \( 2x \) electrons.

### Step 3: Determine Possible Values
- Since the first shell can hold a maximum of 2 electrons, we can set \( x = 2 \). Therefore, the second shell must have \( 2x = 4 \) electrons.

### Step 4: Identify the Element
- Now we need to find an element with 2 electrons in the first shell and 4 electrons in the second shell.
- The electron configuration that matches this is \( 2 \) (for the first shell) and \( 4 \) (for the second shell), which corresponds to the element Carbon (C).

### Step 5: Conclusion
- Therefore, the element that has twice as many electrons in its second shell as in its first shell is **Carbon (C)**.

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