Chemistry
posted by Jill .
How do you calculate the atomic mass of an element when an isotopic composition is given
99.985% 1H; 0.015% 2H
Please show steps to solve!

The idea is the sum of the parts is equal to the whole.
100*avgatomicmass= 99.985*1 + .015*2
solve for avgatomicmass. 
Bob please help further

How???

divide both sides by 100.
then on the right, muliply the terms and add. 
Can you please show how in long form so I know how to do it! Thanks

Help please see last entry

Can you please show how in long form so I know how to do it! Thanks

ANYONE!!!

Here is what Bob Pursley wrote.
100*avgatomicmass= 99.985*1 + .015*2
Here is a rewritten form of his equation although his instructions for solving the equation are simple.
100*x = [99.9985*1 + 0.015*2]
solve for x which is the average atomic mass.