Calculate the atomic mass of gallium if gallium has four naturally occurring isotopes with the following masses and natural abundances:
Ga-69 68.9256 amu 60.11%
Ga-71 70.9247 amu 39.89%
A)69.72 amu
B)69.93 amu
C)70.00 amu
D)69.80 amu
E)70.68 amu

Question

Calculate the atomic mass of gallium if gallium has four naturally occurring isotopes with the following masses and natural abundances:
 Ga-69 68.9256 amu 60.11%
Ga-71 70.9247 amu 39.89%
A)69.72 amu
B)69.93 amu
C)70.00 amu
D)69.80 amu
E)70.68 amu

Quizplus · Accepted Answer

The atomic mass of gallium is the weighted average of the masses of its isotopes. The weighted average is calculated by multiplying the mass of each isotope by its natural abundance and then adding the products together. In this case, the atomic mass of gallium is:(68.9256 amu * 0.6011) + (70.9247 amu * 0.3989) = 69.72 amu

Calculate the Atomic Mass of Gallium If Gallium Has Four