Which of the following statements about the Modern Periodic Table is Correct?

Options

A. It has 18 horizontal rows known as Periods
B. It has 7 vertical columns known as Periods
C. It has 18 vertical columns known as Groups
D. It has 7 horizontal rows known as Groups.

Explanation

To determine which statement about the Modern Periodic Table is correct, let's analyze the characteristics of the Modern Periodic Table step by step.

### Step 1: Understand the Structure of the Modern Periodic Table
The Modern Periodic Table is organized based on increasing atomic number. Elements are arranged in rows (periods) and columns (groups).

**Hint:** Remember that the arrangement is based on atomic number rather than atomic mass, which was a key feature of earlier periodic tables.

### Step 2: Identify the Groups and Periods
In the Modern Periodic Table:
- There are **18 groups** (vertical columns).
- There are **7 periods** (horizontal rows).

**Hint:** Groups contain elements with similar chemical properties, while periods indicate the number of electron shells.

### Step 3: Consider the Modifications Made by Moseley
The Modern Periodic Table was modified by Moseley, who established the concept of atomic number, leading to a more accurate arrangement of elements.

**Hint:** Moseley’s work corrected the order of elements based on atomic number instead of atomic mass, which was a significant advancement.

### Step 4: Evaluate the Statements
Now, we need to evaluate the statements provided in the question. The correct statement should reflect the characteristics we discussed:
- It should mention the 18 groups and 7 periods.
- It should acknowledge the modification by Moseley.

**Hint:** Look for statements that specifically mention the number of groups and periods, as well as the role of Moseley.

### Conclusion
Based on the analysis, the correct statement about the Modern Periodic Table is that it is divided into **18 groups** and **7 periods**.

**Final Answer:** The correct statement is that the Modern Periodic Table is divided into 18 groups and 7 periods.