Question

Calculate the average atomic mass of Mg if the naturally occurring isotopes are Mg - 24, Mg - 25 and Mg - 26. Their masses and abundances are as follows:

Mg - 24 relative atomic mass = 23.985 amu % abundance = 78.70%
Mg - 25 relative atomic mass = 24.986 amu % abundance = 10.13%
Mg - 26 relative atomic mass = 25.983 amu % abundance = 11.17%

Answer 1

24.309

Step-by-step explanation:

mass×percentage+.. = average amu

23.985×78.7/100+24.986×10.13/100+25.983×11.17/100

to three decimal places

=24.309