The member of periods and group in the long form of periodic table are

Options

A. `7` and `9`
B. `8` and `18`
C. `7` and `18`
D. `6` and `10`

Answer

To determine the number of periods and groups in the long form of the periodic table, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Periods**:
- The periodic table is organized into horizontal rows known as periods.
- Each period represents a new energy level of electrons.

2. **Counting the Periods**:
- In the long form of the periodic table, there are a total of **7 horizontal rows** (periods).
- These periods are numbered from 1 to 7.

3. **Understanding Groups**:
- The vertical columns in the periodic table are called groups.
- Each group contains elements that have similar chemical properties.

4. **Counting the Groups**:
- In the long form of the periodic table, there are a total of **18 vertical columns** (groups).
- These groups are numbered from 1 to 18.

5. **Conclusion**:
- Therefore, the long form of the periodic table has **7 periods** and **18 groups**.

### Final Answer:
- The number of periods in the long form of the periodic table is **7** and the number of groups is **18**.