Choose the correct options and fill in the blanks by the correct word.
The atomic number of an element is the number of ____________ (neutrons/protons) in the nuclei of its atoms.

Explanation

To solve the question, "The atomic number of an element is the number of ____________ (neutrons/protons) in the nuclei of its atoms," we need to understand the definition of atomic number.

### Step-by-Step Solution:

1. **Understanding Atomic Number**: The atomic number is a fundamental property of an element. It is defined as the number of protons present in the nucleus of an atom of that element.

2. **Identifying the Options**: The question provides two options: neutrons and protons. We need to determine which of these correctly fills the blank in the statement about atomic number.

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