Question

what is A.m.u? (atomic mass unit )

Answer 1

A.m.u stands for atomic mass unit.
It is also called as molecular mass.

Answer 2

An atomic mass unit or amu is a physical constant equal to one twelfth of the mass of an unbound atom of carbon-12. It is a unit of mass used to express atomic masses and molecular masses. When mass is expressed in amu, it roughly reflects the sum of the number of protons and neutrons in the atomic nucleus(electrons have so much less mass that they are assumed to have a negligible effect).

Calculate the atomic mass of chlorine using the information provided in the following table.

isotope atomic mass
34.96885
36.96590
percent abundance
75.78
24.22

Answer:

To find the atomic mass of chlorine, the atomic mass of each isotope is multiplied by the relative abundance (the percent abundance in decimal form) and then the individual masses are added together.

34.96885 x 0.7578 = 26.50

36.96590 x 0.2422 = 8.95

26.50 + 8.95 = 35.45

The atomic mass of chlorine is 35.45 amu.