A chemical equation is a means

Options

A. of representing chemical and physical properties of reactant molecules
B. of acquiring instructions for the preparation of a compound
C. of representing a chemical change by means of symbols and formulas
D. of showing the kind of elements present in a mixture

Explanation

**Step-by-Step Text Solution:**

1. **Understanding the Chemical Equation**: A chemical equation is a symbolic representation of a chemical reaction. It shows the reactants (the starting substances) and the products (the substances formed as a result of the reaction) along with their respective quantities.

2. **Components of a Chemical Equation**: In a chemical equation, reactants are written on the left side, and products are written on the right side. An arrow (→) is used to indicate the direction of the reaction, showing that reactants are transformed into products.

3. **Example of a Chemical Reaction**: For instance, if we take iron (Fe) reacting with copper sulfate (CuSO4), the equation can be represented as:
\[ \text{Fe (s)} + \text{CuSO}_4 \text{ (aq)} \rightarrow \text{FeSO}_4 \text{ (aq)} + \text{Cu (s)} \]
This shows that iron reacts with copper sulfate to form iron sulfate and copper.

4. **Analyzing the Options**: The question provides multiple options regarding what a chemical equation represents. We need to evaluate each option:
- **Option 1**: "Representing chemical and physical properties of reactant molecule" - This is incorrect because a chemical equation primarily shows the transformation of reactants into products, not just their properties.
- **Option 2**: "Acquiring instruction for the preparation of a compound" - This is also incorrect as chemical equations do not provide instructions for preparation.
- **Option 3**: "Representing a chemical change" - This is correct as a chemical equation illustrates the change that occurs during a chemical reaction.
- **Option 4**: "Showing the kind of elements present in a mixture" - This is incorrect because a chemical equation does not represent mixtures but rather specific reactions.

5. **Conclusion**: The best suitable answer is **Option 3**, which states that a chemical equation represents a chemical change.

---