Question

how many atoms are in 165 g of calcium

Answer 1

\[n=\frac{ m }{ M }=\frac{ N }{ N _{A} }\]

Answer 2

you can use any two sets of the equation depending on what you are given.....
n=no. of moles
m=mass
M=Molar mass (mass of 1 mole of the atom, which can be found on the periodic table)
N=No. of particles (atoms, molecules, ions,....)
Na=Avogadro's constant (6.02 x 10^23)

Answer 3

\[\frac{ 165 }{ 40 }=\frac{ N }{ 6.02 \times 10^{23} }\]
\[N=2.48325 \times 10^{24}\]