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

28.085

Step-by-step 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