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

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

Step-by-step explanation:

`N=n* N_A`

N = Number of atoms/molecules

n = Moles of compound

`N_A` = Avogadro number =
`6.022* 10^(23) mol^(-1)`

We have:

Number calcium atoms =
`N=1.20* 10^(25)`

n = moles of calcium = ?

`n=(N)/(N_A)=(1.20* 10^(25))/(6.022* 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.