Question

Find the atomic mass unit of Silicon-28, Silicon-29, Silicon-30 with masses of 27.977, 28.976, 29.974, respectively.

Answer 1

Answer:

28.085

Explanation:

The formular to obtain average atomic mass unit from isotopes is given as;

sum of (Percentage abundance * Atomic mass) of all isotopes =  Average atomic mass unit

Silicon 28 = 92.23%

Silicon 29 = 4.67%

Silicon 30 = 3.1%

(92.23 / 100  *  27.977) + (4.67 / 100  *  28.976)  +  (3.1 / 100  * 29.974) = Average atomic mass

Average atomic  mass = 25.803 + 1.353 + 0.929 = 28.085