Answer: There are [tex]6.2\times 10^{23}[/tex] atoms of helium are found in a helium balloon if it has 3.9 g of helium inside.
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to the molecular mass and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar Mass}}=\frac{3.9g}{4.00g/mol}=0.975moles[/tex]
1 mole of helium contains = [tex]6.023\times 10^{23}[/tex] atoms
Thus 0.975 moles of helium contain = [tex]\frac{6.023\times 10^{23}}{1}\times 0.975=6.2\times 10^{23}[/tex] atoms
