Solids, Liquids, and Gases Flashcards
(24 cards)
states of matter
the different forms in which a substance can exist; the three basic states are solid, liquid, and gas
kinetic theory
the idea that all substances are made up of moving particles which have varying amounts of energy
Brownian motion
the movement of microscopic particles in liquids and gases; the movement is caused by the particles constantly colliding with the rapidly moving molecules of the fluid in which they are floating
How can we give particles more energy?
Add heat.
Has the kinetic theory been proven?
No. It provides an explanation for how solids, liquids, and gases are seen to behave, and why substances change from one state to another.
Which particles have the least amount of energy?
The particles in a solid have the least amount of energy and so cannot overcome the attraction between one another. They vibrate, but stay where they are.
What happens when we heat a solid?
The heat gives the particles enough energy to escape from each other and become a liquid. We call this melting.
Which particles have the most energy?
The particles in a gas have the most energy. They easily move far apart and spread out through the available space. We call this diffusion.
melting point
the temperature at which a substance turns from a solid into a liquid
boiling point
the temperature at which a substance turns from a liquid into a gas
sublimation
a change from solid to gas (or gas to solid) without going through a liquid form
condensation
the process of a gas cooling enough to become a liquid; also, the droplets of liquid that form as a gas cools
freezing
the process of a liquid cooling enough to become a solid
How do we classify a substance as a solid, a liquid, or a gas?
The classification of a substance as a solid, liquid, or gas depends upon its state at room temperature
evaporation
the process by which the surface molecules of a liquid escape into a vapor
surface tension
a force that pulls together molecules on the surface of a liquid; this is an example of cohesion
cohesion
the attraction of molecules to each other rather than to the molecules of a substance they are touching
adhesion
the attraction of the molecules of one substance to the molecules of another substance it is touching
cohesion
the attraction of molecules to each other rather than to the molecules of a substance they are touching
diffusion
the spreading out of a gas to fill the available space
liquid
a substance that has a definite volume but that flows and changes shape to fill its container
gas
a substance that has no definite volume or shape
solid
a substance that has a definite volume and shape
pressure
the force exerted over a given area by a solid, liquid, or gas
