Which term describes a specific number of particles defined by Avogadro's constant?

Which term describes a specific number of particles defined by Avogadro's constant?

• A. Mole
• B. Current
• C. Potential difference
• D. Electromotive force

Answer: (A)

Counting a fixed number of particles uses the mole. The mole is defined so that one mole contains Avogadro's constant amount of particles, about 6.022 × 10^23. This bridges the tiny world of atoms with measurable amounts of material in grams and lets us relate mass, molar mass, and number of particles. The other terms describe electrical ideas: current is the flow of electric charges per unit time, potential difference is the energy transferred per unit charge between two points, and electromotive force is the energy per unit charge provided by a source. None of these specify a fixed particle count defined by Avogadro's constant.

Counting a fixed number of particles uses the mole. The mole is defined so that one mole contains Avogadro's constant amount of particles, about 6.022 × 10^23. This bridges the tiny world of atoms with measurable amounts of material in grams and lets us relate mass, molar mass, and number of particles. The other terms describe electrical ideas: current is the flow of electric charges per unit time, potential difference is the energy transferred per unit charge between two points, and electromotive force is the energy per unit charge provided by a source. None of these specify a fixed particle count defined by Avogadro's constant.