Question

What is the mass,in grams,of 1.20x10^25 atoms of calcium?

Answer 1

The mass of 1.20x10^25 atoms of Ca is 8000 grams

Answer 2

Answer:

The mass of calcium in the given number of atoms is 797.2 g.

Explanation:

$N=n\times N_A$

N = Number of atoms/molecules

n = Moles of compound

$N_A$ = Avogadro number = $6.022\times 10^{23} mol^{-1}$

We have:

Number calcium atoms = $N=1.20\times 10^{25}$

n = moles of calcium = ?

$n=\frac{N}{N_A}=\frac{1.20\times 10^{25}}{6.022\times 10^{23} mol^{-1}}$

n = 19.93 mol

Atomic mass of calcium = 40 g/mol

Mass of 19.93 moles of calcium = 40 g/mol × 19.93 mol=797.2 g

The mass of calcium in the given number of atoms is 797.2 g.