What is $1$ mole? Write two different methods to represent a mole.

(N/A) $1$ mole is defined as the amount of substance that contains exactly $6.022 \times 10^{23}$ elementary entities (atoms,molecules,ions,or other particles). This number is known as Avogadro's number $(N_A)$.
Two different methods to represent a mole are:
$1$. In terms of mass: $A$ mole is the amount of substance whose mass in grams is numerically equal to its molar mass (atomic or molecular mass).
$2$. In terms of number of particles: $A$ mole is the amount of substance that contains $N_A = 6.022 \times 10^{23}$ particles.