The amount of substance in the SI system of units is represented by

Options

A. candela
B. mole
C. weight
D. kilogram

Answer

To determine the amount of substance in the SI system of units, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Fundamental Quantity**: The question asks about the amount of substance, which is one of the fundamental quantities in physics.

2. **List the Fundamental Quantities**: There are seven fundamental quantities in the SI system: mass, length, time, electric current, temperature, amount of substance, and luminous intensity.

3. **Recognize the Symbol for Amount of Substance**: The amount of substance is represented by the symbol 'n'.

4. **Determine the SI Unit for Amount of Substance**: The SI unit for the amount of substance is the mole, which is abbreviated as 'mol'.

5. **Conclusion**: Therefore, the amount of substance in the SI system of units is represented by the unit 'mole' (mol).

### Final Answer:
The amount of substance in the SI system of units is represented by the unit **mole (mol)**.

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