Term | Definition |
Pollution | the introduction of harmful substances into the environment. |
acid precipitation | when burning fossils fuels causes rain, sleet or snow to become contaminated with acid. |
erosion | is the process by which wind and water move soil from one place to another. |
deforestation | is the process of clearing forest |
nonrenewable resources | an energy resource that cannot be replaced after they are used, or can only be replaced only over thousands or millions of years. |
fossil fuels | formed from the buried remains of plants and animals that lived millions of years agao. |
renewable resources | energy resources that can be used and replaced in a short amount of time. |
physical property | a property of matter that can be observed or measured without changing the identity of the matter. |
chemical property | a property of matter that describes a substance based on its ability to change into a new substance. |
physical change | a change that affects on or more physical properties of a substance, but does not change the substance. |
chemical change | a change that occurs when one or more substances are changed into something new. |
states of matter | the physical forms in which a substance can exist. States include solid, liquid, gas, and plasma. |
solid | a state in which matter has a defined shape and volume. |
liquid | a state in which matter takes the shape of its container. |
gas | a state in which matter changes in both shape and volume. |
change of state | the change of a substance from one state to another. |
motion | an object's change in position relative to a reference point over time. |
speed | the rate at which an object moves |
velocity | the speed of an object in a particular direction. |
acceleration | the rate at which velocity changes; an object can accelerate if it's speed direction, or both change. |
force | a push or pull on an object |
friction | a force that opposes motion between two surfaces that are touching. |
gravity | a force of attraction between objects |
weight | a measure of the gravitational force exerted on an object. It's value can change with the location of the object in the universe. |
mass | the amount of matter that something is made of. Its value does not change no matter where you are in the universe. |