Term | Definition |
atomic mass | average mass of one atom of an element |
periodic table | a chart where all elements are organized into periods and groups according to their properties |
Chemical symbol | one or two letter code that stands for an element; many symbols are abbervaiations of the element name whitch may be english |
period chemistry | a row of elements in the periodic table arranged by atomic number geology unit of geologic time lasting tens of millions... |
group | column of elements in the periodic table, in whitch elements have certain properties in common; also called chemical family |
matter | the material that all objects and substances are made our ; anything that has mass and takes up space. |
element | substances that are the building blocks of all matter; an element is made up of one kind of atom |
compound | matter of two or more elements the elements in a compound are chemically bonded, cannot be seperated by physical means |
atom | smallest particle into whitch an element can be divided and still have the properties of that element |
electron | negatively charged particle found outside the nucleus of an atom |
nucleus biology | structer near the center of a cell that contains the cells DNA chemistry center of an atom made up of protons and neutrons |
proton | positively charged particle with a neutral charge located in the nucleus |
neutron | in an atom paricle with a neutral charge located in the nucleus |
energy level | the amount of energy carried by an electron in an atom; determines the electrons average distance from the nucleus |
isotube | atoms of the same element with diffrent numbers of neutrons in the nucleus and thus diffrent atomic masses |
mass number | amount of matter in something measured in grams |
atomic number | number of protons in the nucleus of one atom of an element |
metal elements | usually soild with a shiny surface metals conduct electricity and thermal energy well |
malleable | a term used to describe material that can be pounded into shape |
ductile | a term used to describe a materials that can be pulled out into a long wire |
conductivity | transfer of heat from a warmer substance through direct contace |
reactivity | the ease and speed with witch an element combines or reacts with other elements and compounds |
corrasion | the gradual wearing away of a metal element due to a chemical reaction |
alkial metal | an element in group 1 of the periodic table |
alkaline earth metal | an element in group 2 of the periodic table |
transition metal | one of the elements in groups 3 through 12 of the periodic |
alloy | a mixture of two or more elements on e of whitch is a metal |
nonmetal | an element that lacks most of the properties of a metal |
diatomic molecule | a molecule consiting of 2 atoms |
halogen | an element found in group 17 of the periodic table |
noble gas | an element that lacks most of the properties of a metal |
metaloid | an element that has some characteristics |
semiconductor | a substance that can conduct electricity under some conditions |