7G - Solids liquids and gases Flashcards
What is the particle theory?
The particle theory is a theory in science that describes all forms of matter as being composed of tiny particles that are always in a constant state of motion.
what are solids?
Solids are made up of particles that are very close
together. (Strong forces of attraction hold the
particles together.)
What are liquids?
Liquids are made up of particles that are fairly close
together. (Quite strong forces of attraction hold the
particles together.)
what are gases?
Gases are made up of particles that are well spread
out. (There are only weak forces of attraction
between the particles.)
What is Brownian motion?
When pollen grains in water are observed through a microscope they are seen to move jerkily in
different directions. This is called Brownian motion. It is caused by water particles, which are
moving all the time, hitting the pollen grains. The pollen grains are small enough so that when
many water particles hit one side of the grain, the grain is moved in that direction.
Brownian motion provides evidence to support particle theory.
What is diffusion?
Diffusion is when two chemicals mix together without anything moving them.
What is dilution?
When you add water to a liquid substance, you dilute it (kind of like making it thinner).
