The smallest matter particle that can take part in chemical reaction is:

Options

A. Atom
B. Molecule
C. Both (A) and (B)
D. None of these

Explanation

To solve the question regarding the smallest matter particle that can take part in a chemical reaction, we can follow these steps:

### Step 1: Understand the Definitions
- **Atom**: An atom is the smallest unit of matter that retains the properties of an element. It cannot be divided into smaller particles while maintaining its chemical properties.
- **Molecule**: A molecule is a group of two or more atoms bonded together, representing the smallest fundamental unit of a chemical compound.

### Step 2: Analyze the Options
The options provided are:
1. Atom
2. Molecule
3. Both A and B
4. None of these

### Step 3: Apply Dalton's Theory
According to Dalton's atomic theory, the atom is the smallest particle that can participate in a chemical reaction. This theory emphasizes that atoms combine in specific ratios to form compounds and that chemical reactions involve the rearrangement of these atoms.

### Step 4: Consider the Role of Electrons
While electrons are involved in chemical reactions (as they are transferred or shared between atoms), they do not exist independently as stable particles. They are subatomic particles that are part of atoms.

### Step 5: Conclusion
Since atoms can exist independently and are the smallest units that can take part in chemical reactions, the correct answer to the question is:
- **Atom**

### Final Answer
The smallest matter particle that can take part in a chemical reaction is: **Atom**.

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