Term | Definition |
Gas | a state of matter where the atoms or molecules are farther apart than in a liquid and moving faster than a liquid; very little or no attraction between particles |
liquid | a state of matter where the atoms or molecules are packed less closely than a solid, but more closely than a gas and are moving more than a solid; some attraction between the particles |
solid | a state of matter where the atoms or molecules are packed closely together and do not move freely; strong attraction between the particles |
molecule | smallest part of a compound with the properties of that compound; two or more atoms chemically bonded together |
particle | atoms or molecules of a substance; compose all matter and are in constant motion |
state of matter | commonly known as solid, liquid or gas; each has characteristic properties |
atom | smallest part of an element with the properties of that element; the basic building blocks of all matter |
atomic mass | the average mass of atoms of an element, it also known as atomic weight. The mass on the Periodic Table of Elements |
column | lines that go up and down/vertically; also called "groups" on the periodic table of elements |
row | lines that go across/horizontally; also called "periods" on the periodic table of elements |
nonmetal | category of elements that do not have the properties of the metals |
mass number | the total number of protons and neutrons in one atom of an element |
atomic number | the number of protons in one atom of and element; is used to identify the element |
electron | a negatively charged particle found outside the nucleus of an atom |
electron cloud | the area surrounding the nucleus of an atom where electrons orbit |
neutron | a particle, same mass as a proton, but with no electric charge; found in the nucleus of an atom |
proton | positively charged particle, found in the nucleus of an atom; quantity is equal to the atomic number/determine the element. |
element | a collection of atoms of one type that cannot be decomposed into any simpler units except by spontaneously changing into other units by radioactive processes. |
Family (of elements) | a grouping of elements based on similar chemical properties; families are generally arranged by columns in the periodic table. |
metal | category of elements that usually have a shiny surface, are generally good conductors of heat and electricity, and can be melted or fused, hammered into thin sheets or drawn into wires |