1. The problem statement, all variables and given/known data I'm having trouble with this. I need to calculate the number of atoms in iron. How do I do this? For example if I had 1 KG of iron, how many atoms are in it? 2. Relevant equations I need to give an answer in scientific notation A x 10^B A being 1 significant figure, and B being whole number 3. The attempt at a solution No idea what to do.