What is the number of atoms in 46 g of sodium-23 (N = Avogadro

What is the number of atoms in 46 g of sodium-23 (N = Avogadro constant)?

N/2
N
2N
23N
This question was previously asked in
UPSC CDS-1 – 2017
The number of atoms in 46 g of sodium-23 is 2N.
The atomic mass of sodium-23 is approximately 23 g/mol. One mole of any substance contains Avogadro’s number (N) of particles (atoms, molecules, etc.). Therefore, 46 g of sodium-23 constitutes (46 g / 23 g/mol) = 2 moles of sodium atoms. The number of atoms is then 2 moles * N atoms/mole = 2N atoms.
Avogadro’s constant (N) is approximately 6.022 x 10^23 mol^-1. This constant represents the number of constituent particles, usually atoms or molecules, that are contained in one mole of a substance.