In the following questions a statement of assertion (A) is followed by a statement of reason ( R)
A: Ionization enthalpy decreases on moving down the group .
R: Force of attraction between nucleus and electrons decreases on moving down the group.

Options

A. If Both Assertion & Reason are true and the reason is the correct explanation of the assertion then mark (1) .
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion then mark (2)
C. If Assertion is true statement but Reason is false then mark (3)
D. If both Assertion and Reason are false statements then mark (4)

Answer

**Step-by-Step Solution:**

1. **Understanding the Assertion (A):**
The assertion states that "Ionization enthalpy decreases on moving down the group." This means that as we move down a group in the periodic table, the energy required to remove an electron from an atom decreases.

**Hint:** Think about how the atomic structure changes as you go down a group.

2. **Understanding the Reason (R):**
The reason provided is that "Force of attraction between nucleus and electrons decreases on moving down the group." This implies that as we go down a group, the attraction between the positively charged nucleus and the negatively charged electrons becomes weaker.

**Hint:** Consider how the distance between the nucleus and the outermost electrons changes as you move down a group.

3. **Analyzing the Relationship:**
The reason provided explains the assertion. As we move down a group, the atomic size increases because additional electron shells are added. This increase in distance between the nucleus and the outermost electrons results in a weaker force of attraction.

**Hint:** Reflect on how increased atomic size affects the ionization energy.

4. **Conclusion:**
Both the assertion and the reason are true, and the reason correctly explains the assertion. Therefore, the answer is that both statements are true, and the reason is the correct explanation for the assertion.

**Final Answer:** Both A and R are true, and R is the correct explanation for A.

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