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kinetic energy

Energy an object has because of its motion

kinetic theory

All matter consists of tiny particles that are in constant motion

Gas Preasure

Force exerted by a gas per unit surface area of an object

Vacuum

Empty space with no particles and no pressure

Atmospheric pressure

Collisions of atoms in molecules in air with objects

Barometer

an instrument that measures atmospheric pressure

pascal

SI unit of pressure

standard atmosphere

a unit of pressure: the pressure that will support a column of mercury 760 mm high at sea level and 0 degrees centigrade

Vaporization

Conversion of a liquid to a gas or vapor

Evaporation

What vaporization occurs at the surface of liquid that is not boiling

vapor pressure

Measure of force exerted by a gas above a liquid

Boiling point

Temperature at which a vapor pressure of liquid is just equal to external pressure on liquid

Normal boiling point

Boiling point of a liquid at a pressure of 101.3 K PA

Melting point

Temperature at which solid changes to liquid

freezing point

Temperature at which liquid changes to solid

Crystal

Particles arranged in an orderly repeating three-dimensional pattern

unit cell

Smallest group of particles with a crystal that retains geometric shape of crystal

Allotropes

Two or more different molecular forms of same element in the same physical state

Amorphous solid

Lacks an order internal structure

Glass

Transparent fusion of product in organic materials that have cooled to a rigid state without crystallizing

Sublimation

Change of a substance from a solid to a vapor without passing through the liquid state

Phase diagram

Gives condition of temperature and pressure at which a substance exist as a solid liquid or gas

Triple point

Only side of conditions at which all three phases can exist in equilibrium with one another

Explain why there is no gas pressure inside a vacuum

Gas pressure is created by particle collisions and there are no particles inside a vacuum

How would the reading on a barometer change if you were to go from a low at tilted to a higher altitude

The barometer would read a lower pressure in higher altitude

How do the intermolecular attraction attraction between particles in a gas compare with those between particles in a liquid

Attractions are much weaker in a gas than in a liquid

What is diamond classified as an allotrope of carbon

It is the same element with a different structure

What is meant by an elastic collision

In an elastic collision energy is transferred between particles

What are the four characteristics of matter in a gaseous state

Fill their containers, exert pressure, have mass, or compressible

Explain the relationship between the kelvin temperature of a substance in the kinetic energy of the particles

The kelvin temperature is directly proportional to the average kinetic energy

How is the average kinetic energy of water molecules affected when you pour hot water into cups at the same temperature as the water

If the temperature does not change the average kinetic energy is not affected

What is significant about the temperature absolute zero

At absolute zero, the motion of particles would theoretically cease

Explain why liquids and gases differ in density in the ability to be compressed

The particles in a gas are relatively far apart compared to the particles in a liquid. Because of the extra spaces between particles, a gas is less dense and easier to compress

Compare the evaporation of a liquid in a closed container with that of liquid and an open container

In both cases, particles with sufficient kinetic energy move from the liquid to the vapor face. In a closed container, a dynamic equilibrium is set up between the contain liquid and is vapor

Explain why increasing the temperature of a liquid increases its rate of evaporation

More molecules have enough energy to escape attractions within the liquid

Describe what happens when a solid is heated to a melting point

The particles have sufficient kinetic energy to overcome the attractive forces holding them in place

How do you convert Celsius to kelvin

Add 273

What takes place only at the surface of a liquid

Evaporation

What pushed down and what pushes up when a liquid is heated? What happens when those forces are equal?

External atmospheric pressure pushes down, vapor pressure pushes up, boiling occurs when equal

Evaporation/boiling

Change from liquid to gas

Condensation

Change from gas to liquid

Sublimation

Change from solid to gas

Deposition

Change from gas to solid