The relative abundance of various isotopes of silicon is as:Si-28=92.23%,Si-29=4.67% and Si-30=3.10%. Calculate the average atomic mass of silicon.

If bromine atom is in the form of say isotopes "_35^79Br (49.7%) and "_35^81Br (50.3%) then calculate the average mass of bromine atom.

Two stable isotopes of lithium "_3^6Li and "_3^7 Li have respective abundances of 7.5% and 92.5%. These isotopes have masses 6.01512 u and 7.01600 u, respectively. Find the atomic mass of lithium.

An inorganic salt gave the following percentage composition : Na= 29.11%, S= 40.51% and O= 30.38%. Calculate the empirical formula of the salt. (At. Mass Na= 23, S=32)

The three stable isotopes of neon: "_10^20 Ne , "_10^21Ne and "_10^22Ne have respective abundances of 90.51%, 0.27% and 9.22%. The atomic masses of the three isotopes are 19.99 u, 20.99 u and 21.99 u,respectively. Obtain the average atomic mass of neon.

Nitrogen occurs in nature in the form of two isotopes with atomic mass 14 and 15 respectively. If average atomic mass of nitrogen is 14.0067, what is the % abundance of the two isotopes ?

Carbon occurs in nature in the form of two isotopes with atomic mass 12 and 13 respectively. If average atomic mass of carbon is 12.011 u , what is the % abundance of the two isotopes ?

B has two isotopes 10B (19%) and 11B( 81%) . What is the atomic mass of B .