Answer: Mole.
- A Mole
- B Temperature
- C Pressure
- D Density
Correct answer: A. Mole
Explanation: The mole connects the mass of a substance with the number of particles it contains.
Mass connects to moles via molar mass, and moles connect to particle count via Avogadro's number or to gas volume via the 22.4 L/mol rule at STP.
Concept context
The mole is chemistry's counting unit. Learn to relate mass, volume, and number of particles using Avogadro's number and molar mass, the foundation of all stoichiometry and reaction calculations.