Which atomic particle has negligible mass?

Options

A. proton
B. electron
C. neutron
D. both proton and neutron

Answer

To determine which atomic particle has negligible mass, we can follow these steps:

### Step 1: Identify the three main atomic particles
The three main atomic particles are:
- Neutrons
- Protons
- Electrons

### Step 2: Understand the properties of each particle
- **Neutrons**: These particles are neutral and are found in the nucleus of an atom. They have a mass of approximately \(1.67 \times 10^{-27}\) kg.
- **Protons**: These particles are positively charged and are also found in the nucleus. Their mass is similar to that of neutrons, approximately \(1.67 \times 10^{-27}\) kg.
- **Electrons**: These particles are negatively charged and orbit around the nucleus. The mass of an electron is approximately \(9.1 \times 10^{-31}\) kg.

### Step 3: Compare the masses of the particles
When we compare the masses:
- The mass of neutrons and protons is about \(1.67 \times 10^{-27}\) kg.
- The mass of electrons is \(9.1 \times 10^{-31}\) kg.

### Step 4: Determine which particle has negligible mass
Since the mass of electrons (\(9.1 \times 10^{-31}\) kg) is significantly smaller than that of neutrons and protons (\(1.67 \times 10^{-27}\) kg), we conclude that electrons have negligible mass compared to the other atomic particles.

### Step 5: Final answer
Thus, the atomic particle that has negligible mass is the **electron**.

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