Question

How many atoms are there in 2.43 g of calcium?

Answer 1

Answer:

Explanation:

We're asked to calculate the number of atoms of

Ca

in

153

g Ca

.

What we must first do is convert the given mass of calcium to moles of calcium, using its molar mass (referring to a periodic table, this is

40.08

g

mol

):

153

g Ca

(

1

mol Ca

40.08

g Ca

)

=

3.82

mol Ca

Using Avogadro's number,

6.022

×

10

23

particles

mol

, we can calculate the number of atoms present:

3.82

mol Ca

(

6.022

×

10

23

atoms Ca

1

mol Ca

)

=

2.30

×

10

24

atoms Ca