How many atoms are in this iron nail?

The atomic mass of iron (Fe) is 55.85 amu. The atomic mass of radium (Ra) is 226 amu. One mole of atoms of any element contains 6.022 X 1023 atoms, regardless of the type of element.

Iron (Fe) has an atomic mass of 55.845 g/mol. So if you have 13.2 grams, you have 13.2/55.845 mol = 0.2364 moles.

Hope this helps!

Explanation:

the potential energy of the reactants is 200j.

from the energy diagram, the energy of the product formed is 350j; this means that, this reaction is an endothermic reaction, because it absorbs energy from its environment.