CONSTANT QUANTITY

"In a closed system, the total energy of the system remains a constant quantity."

"The speed of light in a vacuum is considered to be a constant quantity."

"The Avogadro's number is a constant quantity that represents the number of atoms or molecules in one mole of a substance."

"According to Newton's first law of motion, an object at rest will remain at rest unless acted upon by an external force. This law is based on the principle of constant quantity of motion."

"The ideal gas law equation relates the pressure, volume, and temperature of a gas as a constant quantity."