| Question | Answer |
|---|---|
| Phase of matter | the form in which particles are arranged and move |
| boiling point | the temperature at which a substance changes from a liquid to a gas |
| melting point | the temperature at which a substance changes from a solid to a liquid |
|
A solid has … |
a definite shape and takes up a definite amount of space |
| A solid's particles are… | closely packed together and have some energy, and move back and forth but do not change places |
|
A liquid… |
does not have a definite shape but takes up a definite amount of space |
| A liquid's particles are… | not held in place but are able to slide past one another |
| A liquid takes the shape… | of the container |
|
gases are… |
invisible and do not have a definite shape |
|
Gas takes the shape |
of the container and expands to fill whatever space is available |
| Gas particles are… | very far apart from one another and move in all directions |
| in the gas state, water is called… | water vapor |
| gas does not take up a definite amount of… | space |
| Energy can cause the particles in a substance to move | faster and farther apart. |
| Substances change phase (state or form) when enough heat is | added or taken away. |
| Phase changes are examples of physical changes that can be reversed by | adding or removing energy. |
| Every substance changes phases at a different… | temperature |
| The melting point and boiling point of a substance are both physical properties that help | identify the substance. |
| The temperature at which a substance melts is the same temperature at which it freezes, or changes from a | solid to a liquid. |
| The temperature at which a substance changes from a liquid to a gas is also the temperature at which the substance changes from a | gas back into a liquid. |
| Substances have different melting and boiling points that are much different from | the melting and boiling points of water. |
