Multimolecular sols are:

Options

A. Sol of gold
B. Starch sol
C. Sol of proteins
D. Soap solution

Answer

To determine what multimolecular sols are, we can follow these steps:

### Step-by-Step Solution:

1. **Definition of Multimolecular Sols**:
Multimolecular sols are colloidal systems formed by the aggregation of a large number of atoms or small molecules. These particles have a diameter of less than 1 nanometer and combine in a dispersion medium to form aggregates that fall within the colloidal size range (1 nm to 100 nm).

2. **Characteristics of Multimolecular Sols**:
- The particles in multimolecular sols consist of several atoms or small molecules.
- They exist in a colloidal state, meaning they are dispersed throughout a medium but do not settle out.

3. **Examples of Multimolecular Sols**:
- One common example of a multimolecular sol is **gold sol**, which contains particles of various sizes made up of several gold atoms.
- Other examples include certain types of colloidal solutions that do not fit the definition of multimolecular sols, such as starch sol and protein sol, which are classified as macromolecular colloids.

4. **Analysis of Options**:
- **Option 1: Gold sol** - This is a correct example of a multimolecular sol.
- **Option 2: Starch sol** - This is incorrect; starch is a macromolecular colloid.
- **Option 3: Protein sol** - This is also incorrect; proteins are macromolecular colloids.
- **Option 4: Soap solution** - This is incorrect; soap molecules aggregate to form micelles, not multimolecular sols.

5. **Conclusion**:
The correct answer is **Option 1: Gold sol**, as it is the only example of a multimolecular sol among the options provided.