Question

calculate the relative atomic mass of calcium given that the number of moles in 0.4 moles and mass is 16 g​

Answer 1

The relative atomic mass of Calcium : 40 g/mol

Further explanation

The mole is the number of particles contained in a substance

1 mol = 6.02.10²³

Moles can also be determined from the amount of substance mass and its molar mass / the relative atomic mass(Ar) :

$\tt mol(n)=\dfrac{mass(m)}{Ar}$

Calcium (Ca) :  

moles = 0.4

mass = 16 g

$\tt Ar=\dfrac{mass}{mol}=\dfrac{16}{0.4}=40~g/mol$