| A | B |
|---|
| What is a proton? | Positively charged particles of the nucleus. |
| In what part of the atom is the proton found? | In the nucleus |
| What is a neutron? | Particles of the nucleus that have no charge |
| In what part of the atom is the neutron found? | In the nucleus |
| What is an electron? | Negatively charged particles in the atom. The mass is too small to count. |
| In what part of the atom is the electron found? | In the electron cloud around the nucleus |
| What is the definition of an atom? | The smallest particle into which an element can be divided and still be the same substance. |
| What is the definition of an ion? | An atom with an electrical charge. The atom either lost or gained an electron. |
| What is the Atomic Mass Unit (amu)? | SI unit used to express the masses of particles in atoms. |
| What is an Electron Cloud? | The regions around the nucleus of the atom where electrons are likely to be found. |
| What is an Atomic Number? | The number of protons in the nucleus of an atom. It determines the identity of an element. |
| What is the Mass Number? | The sum of protons and neutrons in an atom. |
| What is Atomic Mass? | The weighted average of the masses of all the naturally occurring isotopes of an element. |
| What is the atomic mass unit of a neutron? | 1 amu |
| Name the scientists who were involed in the history of the atom? | Bohr, Rutherford, Thomson, Dalton, Democritus. |
| What is an isotope? | Atoms with the same number of protons but different numbers of neutrons. |
