| A | B |
|---|
| subatomic particle | proton, neutron, electron |
| proton | subatomic particle that has a positive charge and is found in the nucleus of an atom |
| atomic mass | average of the masses of the existing isotopes of an element |
| neutron | subatomic particle with no electric charge that is found in the nucleus of an atom |
| atomic number | number of protons in the nucleus of an atom |
| isotope | atom of an element that has the same number of protons as another atom of the same element but a different number of neutrons |
| mass number | sum of the protons and neutrons in the nucleus of as atom |
| electron | negatively charged subatomic particle found in an area outside the nucleus of an atom |
| electron cloud | space in which electrons are likely to be found |
| energy level | most likely location in an electron cloud in which an electron can be found |
| period | horizontal row of elements in the peroidic table |
| metal | element that is a good conductor of electricity, is shiny, has a high melting point, is ductile and malleable, and tends to lose electrons |
| luster | shininess |
| ductile | able to be drawn in a thin wire |
| malleable | able to be hammered out into a thin sheet |
| corrosion | gradual wearing away of a metal due to a chemical reaction in which the metal element is changed into a metallic compound |
| nonmetal | element that is a poor conductor of heat and electricity, has a dull surface, low melting point, is brittle, breaks easily, and tends to gain electrons |
| metalloid | element that has properties of both metals and nonmetals |
