| A | B |
|---|
| metal | class of elements characterized by properties of shininess, malleability,ductility and conductivity |
| malleable | describes a material that can be pounded into shapes |
| ductile | describes a material that can be drawn into a thin wire |
| conductivity | the ability of an object to transfer heat or electricity to another object |
| reactivity | the ease and speed with which an element combines or reacts with other elements and compounds |
| corrosive | the way in which acids react with some metals so as to eat away at the metal |
| alkali metals | an element in group 1 |
| alkaline earth metal | an element in group 2 |
| transition metal | an element found in groups 3 through 12 on periodic table |
| alloy | a mixture of two or more elements, of of which is a metal |
| particle accelerator | a machine that moves atomic nuclei at higher and higher speeds until they crash, sometimes forming heavier elements |
| nonmetal | a substance that lacks most properties of the metals |
| diatomic element | a molecule consisting of two atoms of the same element; all nonmetals |
| halogen | an element in group 17; all very reactive nonmetals |
| noble gases | an element located in group 18; all nonreactive nonmentals |
| metalloid | an element thathas properities of both metals and nonmetals |
| semiconductor | a substance that can conduct electricity under some conditions |
| valence electrons | electrons located in an atom's outermost energy level |
| nucleus | central core of an atom that contains protons and neutrons |
| neutron | subatomic particle that has no charge and a mass of 1 AMU |
| proton | a subatomic particle with a positive charge and a mass of 1 AMU |
| electron | a negatively charged subatomic particle that in located outside the atom's nucleus; it has almost zero mass |
| atomic number | the number of protons in an atom's nucleus |
| isotope | atoms with the same number of protons, but a different number of neutrons |
| mass number | the sum of an atom's protons and neutrons |
| ion | a charged atom |
| atomic mass | the average mass of all known isotopes of an element |
| period | a horizontal row of elements in the periodic table |
| group | a vertical column of elements in the periodic table |
| periodic table | a chart of elements showing the repeating pattern and their properties |
