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

Question

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

Quizplus · Accepted Answer

The atomic mass is calculated by multiplying the mass of each isotope by its natural abundance and summing the results: (68.9256 u * 0.6011) + (70.9247 u * 0.3989) = 69.72 u.

Calculate the Atomic Mass of Gallium If Gallium Has Two