Nucleus of an atom is the region where

Options

A. only mass of atoms is densely concentrated
B. only positive charge is densely concentrated
C. both mass and positive charge are densely concentrated
D. neither mass nor positive charge are densely concentrated

Answer

To answer the question "Nucleus of an atom is the region where...", we will analyze the components of an atom and the characteristics of its nucleus step by step.

### Step-by-Step Solution:

1. **Understanding the Structure of an Atom**:
- An atom consists of a nucleus at its center and electrons that orbit around this nucleus. The nucleus is much smaller than the entire atom but contains most of the atom's mass.

**Hint**: Remember that the nucleus is at the center of the atom.

2. **Components of the Nucleus**:
- The nucleus is made up of two types of subatomic particles: protons and neutrons. Protons carry a positive charge, while neutrons are neutral (no charge).

**Hint**: Identify the particles that make up the nucleus.

3. **Mass Concentration**:
- The majority of an atom's mass is concentrated in the nucleus because protons and neutrons are much more massive than electrons. Electrons have negligible mass compared to protons and neutrons.

**Hint**: Consider where the mass of the atom is located.

4. **Charge Concentration**:
- The nucleus is positively charged due to the presence of protons. Neutrons do not contribute to the charge. Therefore, the nucleus is the region where positive charge is concentrated.

**Hint**: Think about the charge of the particles in the nucleus.

5. **Conclusion**:
- Based on the above points, we can conclude that the nucleus of an atom is the region where both mass and positive charge are densely concentrated.

### Final Answer:
The nucleus of an atom is the region where both mass and positive charge are densely concentrated.