Atomic number of an element indicates

Options

A. the number of electrons in the nucleus
B. the number of neutrons in the nucleus
C. the number of protons in the nucleus
D. valency of an element.

Answer

To solve the question "Atomic number of an element indicates," we will analyze the options provided and determine which one correctly describes what the atomic number represents.

### Step-by-Step Solution:

1. **Understanding Atomic Number**:
- The atomic number is denoted by the symbol 'Z'. It is a fundamental property of an element.

2. **Analyzing the Options**:
- **Option A: The number of electrons in the nucleus**:
- This is incorrect. Electrons are not located in the nucleus; they orbit around it.
- **Option B: The number of neutrons in the nucleus**:
- This is also incorrect. The atomic number does not represent neutrons; neutrons are part of the mass number, not the atomic number.
- **Option C: The number of protons in the nucleus**:
- This is correct. The atomic number is defined as the total number of protons present in the nucleus of an atom.
- **Option D: Valency of an element**:
- This is incorrect. Valency is related to the ability of an atom to bond with other atoms and is not directly indicated by the atomic number.

3. **Conclusion**:
- Based on the definitions and analysis of the options, the correct answer is **C: The number of protons in the nucleus**.

### Final Answer:
The atomic number of an element indicates the number of protons in the nucleus.

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