Question

what is the atomic mass of hafnium if, out of every hundred atoms ,5 have a mass of 176,19 has a mass of 177,27 have a mass of 178,14 have a mass of 179,35 have a mass of 180​

Answer 1

Answer:

Average atomic mass of Hafnium

=

178.55

amu

Explanation:

If there are two isotopes an element

Average atomic mass

=

mass

a

×

fract

a

+

mass

b

×

fract

b

In the given problem about Hafnium, 5 isotopes have been given.

Extending the above expression to 5 isotopes

We obtain

Average atomic mass

=

176

×

0.05

+

177

×

0.19

+

178

×

0.27

+

179

×

0.14

+

180

×

0.35

=

178.55