If Billy Bob Joe creates 0.21 mol CO2, how many moles of water did he make?

Achange in the number of neutrons in an atom will change an blank . when the number of protons changes in an atom, a new element will form.

Consider the elements bromine and chlorine; which elements has a larger ionic radius ?

The volume of helium in a blimp is 6.28 x 10^9 millimeters. the density of helium in the blimp is .1786 kilogram/meter^3. find the mass of the helium in the blimp.