An atom consists of the sub-atomic particles protons, electrons, and ___________

Explanation

To answer the question, "An atom consists of the sub-atomic particles protons, electrons, and ___________", we need to identify the third type of subatomic particle that is present in an atom.

### Step-by-Step Solution:

1. **Identify the Subatomic Particles**:
- An atom is made up of three main types of subatomic particles: protons, electrons, and neutrons.

2. **Define Each Particle**:
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