In which of the following group of periodic table melting and boiling point increase as we go down the group?

Options

A. Group 1
B. Group 2
C. Group 17
D. Group 13

Answer

To solve the question of which group in the periodic table has increasing melting and boiling points as we go down the group, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Groups**: First, we need to identify the groups in the periodic table. The relevant groups to consider are Group 1 (alkali metals), Group 2 (alkaline earth metals), Group 17 (halogens), and Group 18 (noble gases).

2. **Understand the Nature of Elements in Each Group**:
- **Group 1**: Alkali metals (Li, Na, K, etc.) are metals. Generally, the melting and boiling points of metals decrease down the group.
- **Group 2**: Alkaline earth metals (Be, Mg, Ca, etc.) are also metals. Similar to Group 1, the melting and boiling points tend to decrease down the group.
- **Group 17**: Halogens (F, Cl, Br, I, At) are non-metals. As we move down this group, the size of the atoms increases, leading to stronger Van der Waals forces of attraction between molecules.
- **Group 18**: Noble gases (He, Ne, Ar, Kr, Xe, Rn) are non-metals, but their melting and boiling points are very low and increase only slightly down the group.

3. **Analyze Melting and Boiling Points**:
- In **Group 17**, as we go from fluorine (F) to iodine (I), the melting and boiling points increase. This is due to the increase in molecular size and the resulting increase in Van der Waals forces of attraction.
- In contrast, for Groups 1 and 2, the melting and boiling points decrease as we move down the group.

4. **Conclusion**: Based on the analysis, the only group where melting and boiling points increase as we go down the group is **Group 17 (halogens)**.

### Final Answer:
The correct answer is **Group 17 (halogens)**.

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