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 ...

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 ...

Most of the mass of an atom is found in the nucleus ... Changes to the atomic model Atoms can be broken down into smaller parts. An atom is made of tiny negatively charged electrons dotted ...