Questions: What determines the atomic number of an atom?
A. The number of protons
B. The mass
C. The charge
D. The number of neutrons
Transcript text: What determines the atomic number of an atom?
A. The number of protons
B. The mass
C. The charge
D. The number of neutrons
Solution
Solution Steps
Step 1: Understanding Atomic Number
The atomic number of an atom is a fundamental property that defines the identity of an element. It is represented by the symbol \( Z \).
Step 2: Identifying the Correct Determinant
The atomic number is determined by the number of protons in the nucleus of an atom. Each element has a unique number of protons, which distinguishes it from other elements.
Step 3: Evaluating the Options
A. The number of protons: This is correct, as the atomic number is defined by the number of protons.
B. The mass: This is incorrect, as atomic mass is determined by the total number of protons and neutrons.
C. The charge: This is incorrect, as charge is related to the balance of protons and electrons.
D. The number of neutrons: This is incorrect, as neutrons do not determine the atomic number.
Final Answer
The answer is \(\boxed{\text{A. The number of protons}}\).