The atoms are very attracted to one another and held tightly together. This is why a solid keeps its shape, meaning solid has a definite shape and occupies a definite space (volume).
The attractions between the molecules in liquids are strong enough to keep the molecules close to each other, but they can move past one another. This is why a liquid has undefined shape but occupies a definite space.
The attractions between the molecules of a gas are too weak to bring the molecules together. This is why gas molecules barely interact with one another and are very far apart.
Anything that has mass and takes up space
2 or more different elements chemically combined in a molecule
Groups of two or more atoms (same or different) held together by chemical bonds
The process of transferring energy by direction contact between the two objects
thermal/ kinetic energy
When in particles of a substance have more kinetic or thermal energy (the energy of motion) the faster they move.
Where enough kinetic energy has been added to or removed from a substance so that the particles that make up that substance change how they behave, but the type of substance does not change.
states of matter
The physical forms of matter, which include solid, liquid, and gas