| A | B |
|---|
| astronomy | the study of objects in space |
| hypothesis | a prediction that can be tested |
| variable | a factor in an experiment that changes |
| mass | the amount of matter in an object |
| meteorology | the study of weather conditions |
| weight | a measure of gravitational pull |
| International System of Units (SI) | a modern version of the metric system |
| atom | building block of matter |
| neutron | particle with no electric charge |
| matter | anything that takes up space and has mass |
| electron | moves around the nucleus of an atom |
| element | composed of only one type of atom |
| density | mass divided by volume |
| compound | two or more atoms combine to form this building block of compounds |
| ions | electrically charged atoms |
| proton | particles found in the nucleus of an atom with a positive charge |
| isotopes | atoms of the same element that have different numbers of neutrons |
| physical properties | properties that you can observe without changing a substance into a new substance |
| states of matter | solid, liquid, gas, plasma |
| mixture | a combination of different substances that keep their own properties |
