| A | B |
|---|
| AMU | another name for atomic mass unit |
| atom | smallest particle of an element that has the properties of that element |
| atomic mass | average of the masses of all the existing isotopes of an element |
| atomic mass unit | unit used to measure the masses of subatomic particles; a proton has a mass of 1 amu |
| electromagnetic force | force of attraction or repulsion between particles in an atom |
| electron | subatomic particle with a negative charge |
| electron cloud | space in which electrons are likely to be found |
| energy level | most likkely location in an electron cloud in which an electron can be found |
| gravity | force of an attraction between all objects in the universe |
| 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 protons and the neutrons in the nucleus of an atom |
| matter | anything that has mass or volume |
| neutron | subatomic particle with no electric charge |
| nucleus | small dense positivly charged center of an atom |
| proton | subatomic partice with a positive charge |
| quark | particle that makes up all other known particles in a nucleus of an atom |
| strong force | force that binds protons and neutrons in the nucleus |
| subatomic particle | proton,neutron, or electron |
| weak force | force that is responsible for radioactive decay |
| ductile | able to be drawn into a thin wire |
| family | column of elements in the periodic table |
| group | column of elements in the periodic table |
| malleable | able to be hammered into a thin sheet |
| metal | element that is a good conductor of heat and electrcity; is shiny, has a high melting point, is ductile and malleable, and forms postive ions |
| metaloid | element that has properties of both metals and non metals |
| non metal | element that is a poor conductor of heat and electricity, has a dull surface, low melting point, is brittle, breaks easily, and forms negative ions |
| period | horizontal row of elements in the periodic table |
| peirodic | repeating accoring to the same pattern |
| periodic law | law that states that the physical and chemical properties of hte same elements are periodic funtions of their atomic number. |
