Kinetic Theory and the States of Matter

Kinetic Theory All matter (solids, liquids, and gases) are made up of particles. The kinetic theory states that subatomic particles of all matter are in constant, random motion. The energy of these moving particles is called kinetic energy.

Temperature Temperature - measure of the average kinetic energy of the particles in an object –temperature low, energy low –temperature high, energy high See what happens to the molecules when you change the temperature: mperature/temperature.htm

Absolute Zero Absolute zero - theoretical temperature when the kinetic energy of an object is zero; temperature at which matter stops moving This would be: 0 K, -273 C, F How close have we gotten? 100 pK as of January 2008

There are 4 phases or states of matter. Solid – definite shape and volume Liquid – definite volume and takes shape of its container Gas – takes shape and volume of its container Plasma

Solid Even the particles in a solid move around - but not much. The particles that make up the solid are always vibrating from side to side and up and down. If you give a solid some energy then the particles will move around a little bit more. This is what happens when you heat up a solid piece of wax - give it too much heat and the solid wax will turn into a liquid (or melt).

Types of Solids CrystallineAmorphous

Crystal A crystal is a solid in which the particles are packed in a regularly ordered, repeating pattern extending in all three dimensions. This is called a crystal lattice. Examples: salt, ice, diamond, metals

Amorphous An amorphous solid is one that loses its shape under certain circumstances. Examples: wax, rubber, tar, glass, cotton candy

Now answer these questions. All solids, liquids and gases are made out of what ? Are the particles moving or still ? Do the particles in a solid move ? What do you give a solid to make the particles move more ? What sort of energy could you give wax to turn it into liquid ? When they are hot do the particles move more or less ?

What is the name of the process in which a solid turns into a liquid ? Do the particles in a liquid move more or less than a solid? If you took energy out of a liquid would it turn into a gas or a solid ? What is the name of the process in which liquid water turns into solid ice?

Liquid Particles will flow or glide over one another, but stay toward the bottom of the container. Motion is a bit more random than that of a solid.

Viscosity Viscosity – the resistance of a liquid to flow High viscosity examples – lotion, honey, shampoo Low viscosity examples – water, vinegar, rubbing alcohol, pop

Now, answer these questions. Liquids are made out of what ? Liquid particles are always doing what ? A liquid will take up the shape of a what ? If you tip over a container of liquid, the liquid will do what ? What type of viscosity would maple syrup have?

Plasma An ionized gas that conducts electricity Most common state of matter in the universe and the least common state on Earth Found in the sun and stars as a product of nuclear fusion Found on Earth in fluorescent light tubes

Gas Particles are constantly moving in straight lines (like hockey pucks). When the particles collide with each other, or with the walls of a container, they bounce back. The kinetic energy of the particle is greater than the attractive force between them, so they are much farther apart than particles of a solid or liquid.

Gases are compressible. Gases are compressible because the particles are so much farther apart than those of liquids and solids. What are the relationships between pressure, volume, and temperature of a gas? Lab investigations

Elastic Collision Collision with the walls of the container or with other particles in which no kinetic energy is lost Ideal gas – gas that has elastic collisions; Except at low temperatures and high pressures, most gases can be considered ideal

Pressure Force acting on a unit area of surface Atmospheric pressure – pressure exerted by the Earth’s atmosphere; 14.7 lb/in 2

Now, answer these questions. All gases are made out of what ? Are gas particles moving or still ? Is there a bigger or smaller distance between gas particles compared with liquid ones ? Which particles are the closest together: solid, liquid or gas ? Which particles have the most energy: solid, liquid or gas ? Does a gas take up the shape of a container, yes or no ? When gas particles bounce off walls they exert what ?

Molecule Movement Compare movement in solid, liquid, & gas by clicking on the link below: chemistry/animations/CHE1.1-an- threestates.shtml