BellworkMonday, 10/27

• In a population of spiders there are three different sizes: small, medium, and large. The large spiders are easily seen by predators. Small spiders have a difficult time finding food. What will most likely happen to the population after many generations?

• a.Small and medium spiders will be the least plentiful

• b.Large spiders will learn to hide from predators

• c.Medium spiders will be the most plentiful

• d.Small and large spiders will mutate

• Defend your answer in one complete sentence!

Chapter 8States ofMatter

•Objective:•Describe three states of matter.

•The states of matter are the physical forms in which a substance can exist.

•Matter is made up of tiny particles called atoms and molecules.

•These particles are always in motion and are always bumping into one another

• There Are Three states of matter:

• 1. A solid is the state of matter that has a definite shape and volume

• The particles in a solid do not move fast enough to overcome the attraction between them.

• Each particle vibrates in place and is locked in place by the particles around it.

There Are Two Kinds of Solids:

• 1. Crystalline solids have a very orderly, three-dimensional arrangement of particles.

•2. Amorphous solids are made of particles that do not have a special arrangement.

•2. Liquid is the state of matter that has a definite volume and but takes the shape of its container.

•The particles of a liquid move fast enough to overcome some of the attraction between them.

•So, the particles in a liquid slide past each other.

Liquids have two special

properties:•Surface tension is a force that acts on the particles at the surface of a liquid.

•Viscosity is a liquid’s resistance to flow.

•3. Gas is the state of matter that has no definite shape or volume.

•The particles of a gas move quickly and can break away completely from one another.

•The amount of empty space between gas particles can change.

•Objective: Describe how energy is involved in changes of state.

•A change of state is the change of a substance from one physical form to another.

•Changes of State:•1. Solid to Liquid•2. Liquid to Solid•3. Liquid to Gas•4. Gas to Liquid•5. Solid to Gas

•1. Melting is the change of state from a solid to a liquid.

•The temperature a solid changes to a liquid is its melting point.

•Adding energy to a substance during a change of state is called an endothermic change.

•2. Freezing is the change of state from a liquid to a solid.

•The temperature a liquid changes to a solid is its freezing point.

•Removing energy to a substance during a change of state is called an exothermic change.

•3. Evaporation is the change of state from a liquid to gas. Evaporation occurs at the surface of a liquid that is below its boiling point.

•Boiling is the change of a liquid to a gas throughout the liquid. The temperature a liquid boils is its boiling point.

•4. Condensation is the change of state from a gas to a liquid. The condensation point is the temperature a gas becomes a liquid.

•5. Sublimation is the change of state where a solid changes directly into a gas.

•Objective:•Identify the two changes that can happen when a substance loses or gains energy.

•When most substances lose or gain energy, one of two things happen to the substance: temperature changes or state changes.

•But the temperature of a substance does not change during the change of state.