Posted by Heather on .
Average density of a coppercoated iron BB is 8.00g/mL. If the density for copper is 8.92 g/mL, and the density for iron is 7.43g/mL, what is the percentages of copper and iron in a BB?

chem 111 
DrBob222,
Bob Pursley answered this for you earlier. If you have a specific problem, show your work to where you get stuck, explain what you don't understand for the next step and perhaps someone can help you through it.

chem 111 
Heather,
well i did the problem to my understanding and I ended up getting this: fraction for for Fe: .004 and for Cu: .006?? and he said it should equal 1?? where did I go wrong it equals .01??

chem 111 
Heather,
I was wondering if you could tell me if the answer is Fe: 40% and Cu: 60%???

chem 111 
bobpursley,
In my explaination, I used fraction or decimal percents, not percents. a fraction percent of .4 is 40 percent.