| A | B |
|---|
| matter | anything that has mass and takes up space |
| atom | small particle that makes up most types of matter |
| law of conservation of matter | states that matter is not created or destroyed-it only changes form |
| electrons | negatively charged particles |
| nucleus | positively chaged central part of the atom |
| protons | positively charged particles |
| neutrons | uncharged particles |
| element | matter made of only one kind of atom |
| atomic number | tells you the number of protons in the nucleus of each atom |
| isotopes | atoms of the same element that have different numbers of neutrons |
| mass number | number of protons plus the number of neutrons an atom contains |
| atomic mass | weighted average mass of the isotopes of an element |
| metals | element that is malleable, ductile, a good conductor of electricity, and generally has a shiny or metallic luster |
| nonmetals | elements that are usually gases or brittle solids and poor conductors of electricity and heat; are the basis of the chemicals of life |
| metalloids | element that has the characteristics of both metals and nonmetals and is a solid at room temperature |
| substance | matter that has the same composition and properties throughout |
| compound | substance whose smallest unit is made up of atoms of more than one element bonded together |
| mixture | a combination of compounds and elements that has not formed a new substance and whose proportions can be changed without changing the mixture's identity |
