Question

calculate the number of atom in 80 u of Ca.​

Answer 1

Prove that the bisectors of two adjacent supplementary angles include

a right angle.

Answer 2

First, calculate no of moles by divide calcium mass over molar mass of calcium n = ms ÷ Mwt = 80 ÷ 40 = 2 mol

Number of atoms = no of moles × Avogadro's Number

$\mathtt{Nu = n\times Na= 2\times6\times10^{23}=1.2\times10^{24}}$