An atom is so small that a single drop of water contains more than a billion atoms. Although tiny, atoms are mostly empty space. The simplified model of the atom is that of a cloud of negative ...

It also tells us that chlorine has 18 neutrons (35 - 17) and, as the number of electrons and protons are equal in a neutral atom, chlorine also has 17 electrons. The relative mass of a nucleus is ...

For example, the mass number of argon atoms and calcium atoms can both be 40. The atomic number of a chlorine atom is 17 and its mass number is 35. Calculate the number of protons, neutrons and ...

As they studied atomic disintegration, they kept seeing that the atomic number (number of protons in the nucleus, equivalent to the positive charge of the atom) was less than the atomic mass ...