the formula for carbon dioxide is CO 2. It has one carbon atom (relative atomic mass = 12.0) and two oxygen atoms (relative atomic mass = 16.0): M r of CO 2 = 12.0 + 16.0 + 16.0 = 44.0 It could ...

work out how many atoms of each element are in the chemical formula add together the A r values for all the atoms of each element ...

is a fundamental equation in quantum mechanics that describes how the quantum state of a physical system changes over time. In atomic and molecular physics, various methods have been developed to ...

was less than the atomic mass (average mass of the atom). For example, a helium atom has an atomic mass of 4, but an atomic number (or positive charge) of 2. Since electrons have almost no mass ...