What is the atomic number of an element of period 2 and group 17 of the periodic table?

Options

A. 10
B. 9
C. 17
D. 19

Explanation

To find the atomic number of an element in period 2 and group 17 of the periodic table, we can follow these steps:

### Step 1: Identify the Period and Group
- We are looking for an element in **period 2** and **group 17** of the periodic table.

### Step 2: List the Elements in Period 2
- The elements in period 2 are:
1. Lithium (Li) - Atomic number 3
2. Beryllium (Be) - Atomic number 4
3. Boron (B) - Atomic number 5
4. Carbon (C) - Atomic number 6
5. Nitrogen (N) - Atomic number 7
6. Oxygen (O) - Atomic number 8
7. Fluorine (F) - Atomic number 9
8. Neon (Ne) - Atomic number 10

### Step 3: Identify the Element in Group 17
- Group 17 elements are known as halogens. In period 2, the only halogen is **Fluorine (F)**.

### Step 4: Determine the Atomic Number
- The atomic number of Fluorine is **9**.

### Final Answer
- Therefore, the atomic number of the element in period 2 and group 17 is **9** and the element is **Fluorine**.

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