Which of the following pairs of elements are members of the same group? K and Sr Ar and Cl Si and Ca O and S

Options

A. K and Sr
B. Ar and Cl
C. Si and Ca
D. O and S

Explanation

To determine which pairs of elements are members of the same group in the periodic table, we need to identify the group number for each element in the pairs given in the question.

### Step-by-Step Solution:

1. **Identify the Elements and Their Groups:**
- **Potassium (K)**: Potassium is in Group 1 (or 1A) of the periodic table.
- **Strontium (Sr)**: Strontium is in Group 2 (or 2A) of the periodic table.
- **Argon (Ar)**: Argon is in Group 18 (or 0 group, noble gases) of the periodic table.
- **Chlorine (Cl)**: Chlorine is in Group 17 (or 7A) of the periodic table.
- **Silicon (Si)**: Silicon is in Group 14 (or 4A) of the periodic table.
- **Calcium (Ca)**: Calcium is in Group 2 (or 2A) of the periodic table.
- **Oxygen (O)**: Oxygen is in Group 16 (or 6A) of the periodic table.
- **Sulfur (S)**: Sulfur is also in Group 16 (or 6A) of the periodic table.

2. **Compare the Groups:**
- **Pair 1: K and Sr**: K (Group 1) and Sr (Group 2) - Not the same group.
- **Pair 2: Ar and Cl**: Ar (Group 18) and Cl (Group 17) - Not the same group.
- **Pair 3: Si and Ca**: Si (Group 14) and Ca (Group 2) - Not the same group.
- **Pair 4: O and S**: O (Group 16) and S (Group 16) - Same group.

3. **Conclusion:**
The only pair of elements that are members of the same group is **Oxygen (O) and Sulfur (S)**, which both belong to Group 16.

### Final Answer:
**O and S** are members of the same group.

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