Krypton in a natural sample, which is 0.83% 78kr (molar mass 77.92 g/mol), 1.75% 80kr (molar mass 79.91 g/mol), 11.13% 82 kr (molar mass 81.91 g/mol), 12.09% 83 kr (molar mass 82.92 g/mol), 56.82% 84kr (molar mass 83.91 g/mol), and 17.38% 86kr (molar mass 85.91 g/mol).

The relative atomic mass is 83.795592 amu

Explanation:

To calculate the relative atomic mass of krypton, we take into account, the isotopic masses.

Let’s label each by A - F. We multiply each by its appropriate percentage and add up.

A. 0.83/100 * 77.92 = 0.646736

B. 1.75/100 * 79.91 = 1.398425

C. 11.13/100 * 81.91 = 9.116583

D. 12.09/100 * 82.92 = 10.025028

E. 56.82/100 * 83.91 = 47.677662

F. 17.38/100 * 85.91 = 14.931158

Adding all together will yield = 83.795592 a.m.u

a) the particles of the chair are strongly held together.