You want to calculate the average atomic mass of a sample of Nickle. There are 32 atoms of Nickle-60 and 89 atoms of Nickle-57. What is the percent distribution of Nickle-60?
What is the percent distribution of Nickle-57?
What is the average atomic mass of the sample? Round to the correct number of decimals and include units?

Average atomic mass  = 57.79 amu

Percent contribution of Ni-60 = 26.45%

Percent contribution of Ni-5 =  73.55%

Explanation:

Given data:

Number of atoms of Ni-60 = 32

Number of atoms of Ni-57 = 89

Percent distribution of both isotopes = ?

Average atomic mass of sample = ?

Solution:

Percent contribution:

Total number of atoms = Ni-60 + Ni-57

Total number of atoms = 32 +89 = 121

Percent contribution of Ni-60 = 32/121×100

                                             =   26.45%

Percent contribution of Ni-57 = 89/121×100

                                             =  73.55%

Average atomic mass:

Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass)  / 100

Average atomic mass  = (26.45×60)+(73.55×57) /100

Average atomic mass =  1587 + 4192.35 / 100

Average atomic mass  = 5779.35 / 100

Average atomic mass  = 57.79 amu.