States (Phases) of Matter Vocabulary
Boiling/Boiling Point- The application of heat to change something from a liquid to a
gas. The boiling point is the temperature at which a liquid boils at a fixed pressure. The
boiling point is the same as the temperature of condensation. Occurs inside the liquid and
at the surface.
Bose-Einstein Condensate- The fifth state of matter, only a few billionths of a degree
above -2730C or Absolute Zero. This super-cooled state has the atoms lose their
individual properties and form into one big blob. It has less energy than a solid, and is
called a “super-atom”.
Condensation- The change of a gas or vapor to a liquid, either by cooling or by
increasing pressure. When water vapor cools in the atmosphere, for example, it
condenses into tiny drops of water, which form clouds.
Deposition- The opposite of sublimation, where a gas changes directly into a solid;
gaseous vapor turning into frost. Ex. Frost forming on the windshield, the night after
it does not rain or snow---warm air (with water vapor) hits the much colder
windshield.
Energy- the ability to do work; when changing from one state of matter to another,
energy in the form of heat must be added or taken away.
Evaporation- A form of vaporization. The ability to convert or change the substance
into a vapor from a liquid state. Occurs at the surface of a liquid, at a temperature
below the boiling point.
Freezing/Freezing Point- To pass from the liquid to the solid state by loss of heat. The
freezing point is the temperature at which a liquid of specified composition solidifies
under a specified pressure.
Gas- The state of matter that has no fixed size or shape. It has the ability to diffuse
readily throughout a container and distribute evenly throughout.
Heat- the energy transferred from one substance to another. This is due to a
temperature difference, and as a result it is transferred from where there is more heat
energy to where there is less.
Kinetic Theory- The theory that molecules will move constantly and randomly and will
often collide with each other. They also collide with the walls of any container they may
be in. Adding heat will increase molecular movement and collisions; removing heat will
decrease molecular movement and collisions
Liquid- A state of matter that shows a readiness to flowing, it has no fixed shape, taking
on the shape of its container, but it does have a fixed volume. EXAMPLES- Mercury,
liquid H2O, ammonia, vinegar
Melting/Melting Point- To pass from the solid state to the liquid state by the gain of
heat. The melting point is the same as the freezing point of a substance. Ex. Ice
changing into liquid.
Molecules- the smallest identifiable part of a substance; the combination of two or more
atoms (these may be the same or different atoms; O2 or H2O are both molecules)
Phase Change- a change from one state of matter (solid or liquid or gas) to another
without a change in chemical composition. It is caused by adding or taking away heat
energy. A physical change.
Plasma- The 4th state of matter, most similar to a gas, (but consisting of positively
charged ions with most or all of their detached electrons moving freely about). Produced
by high temperatures, and existing mostly in space (such as the Sun and stars), but also in
fluorescent light bulbs and neon signs.
Solid- A state of matter that keeps a definite size and shape. The molecules move
around, but only slightly (shivering, in the case of water). EXAMPLES- Wood, skin,
pencil, ice.
Sublimation- The process of changing from a solid to a gas without passing through an
intermediate liquid phase. Carbon dioxide, at a pressure of one atmosphere, sublimates at
about -78 degrees Celsius. Nitrogen sublimates from solid form as well, with vapor
coming off.
Surface Tension- The attraction of water molecules for each other (cohesion) at the
surface of a liquid. This “skin” that is produced can resist external forces and allow
things to sit/stand on water that may even be denser than water itself.
Temperature- a measure related to the motion of atoms, ions or molecules of a
substance.
Vaporization- the process of becoming a vapor; conversion of a substance from the
liquid or solid phase into the gaseous (vapor) phase. Boiling and evaporation are both
examples of the phase change of vaporization.
Viscosity- The resistance of a substance (a liquid or a gas) to flow. The viscosity
increases as density increases. EXAMPLE: Maple syrup has greater viscosity than
water, because it flows more slowly.