Question

The most accurate statement with regard to the significance of Avogadro's number, $6.02\times {10}^{23}$.

• A. It is the conversion factor between grams and atomic mass units
• B. It is a universal physical constant just as the speed of particle
• C. It is the number of particles that is required to fill a $1$-liter container
• D. It is the inverse diameter of an $H$ atom
• E. It is the number of electrons in the universe

Answer 1

The correct option is A It is the conversion factor between grams and atomic mass units

Avogadro's number ($6.022\times {10}^{23}$) is the conversion factor between the grams and atomic mass units.
Example:
Atomic mass unit of $O$-atom $=16u$
Actual mass of $O$-atom $=\frac{16}{6.022\times {10}^{23}}=2.7\times {10}^{-23}g$
As $6.022\times {10}^{23}$ O-atoms have $16g$ molar mass, which is the same numerical value for atomic mass but a different unit, i.e., $amu$ = atomic mass unit (amu).