Label each picture as the correct state of matter.

A B C

3.1: Solids, Liquids and

Gases

What are the three common states of matter and how do they differ?

• Three states of matter are:1. Solid2. Liquid3. Gas

• Classified based on whether their shapes and volumes are definite or variable.

• What do these four objects have in common?– Pencil, cell phone, book, and a quarter

• They all have a recognizable shape and they all take up a certain amount of space.

• They are classified as SOLIDS.– state of matter in which materials have a definite

shape and a definite volume.

Solids• State of matter in which materials

have a definite shape and a definite volume.• Almost all solids have some type

of orderly arrangement of particles at the atomic level.

Liquids• State of matter in which a

material has a definite volume but not a definite shape.

• liquid always has the same shape as its container and can be poured from one container to another.

• Atoms arranged close together but more random than those in a solid.

Gases• State of matter in which a

material has neither a definite shape nor a definite volume. • Takes the shape and volume of

its container.• Random arrangement of atoms• Example: Air-mixture of gases

Gases• Helium filled balloons, a

colorless gas that is less dense than air. The “shape” of the helium in a balloon is the same as the shape of the balloon itself. The volume of the helium in a balloon is equal to the volume of the balloon.

Plasma• State of matter in which atoms have

been stripped of their electrons• Found in stars, solar wind, lightning

and other EXTREMELY hot places.

Phase Changes• Occurs when a substance changes from one state of

matter to another• Six common phase changes:– Melting– Freezing– Vaporization– Condensation– Sublimation– Deposition

What change is taking place?• Melting = solid to liquid *• Freezing = liquid to solid• Vaporization= liquid to gas *• Condensation = gas to liquid• Sublimation = solid to gas *• Deposition = gas changes to solid

without changing to liquid first

Phase Change Flow Chart

Endothermic vs. Exothermic

• Endothermic-absorbs energy in the form of heat– Melting– Vaporization– Sublimation

• Exothermic-releases energy in the form of heat– Freezing– Condensation– Deposition

Temperature and Energy• All phase changes share characteristics

related to energy and temperature.• The temperature of the substance does

not change during a phase change.• Energy is either absorbed (endothermic)

or released (exothermic) during the phase change.

Phase Change Diagram

Endothermic Processes• Heat of Fusion = the

energy a substance must absorb in order to change from SOLID to LIQUID– “Fusion” is another term

for melting– Varies depending on

substance– Ex: I g of ice absorbs 334

J of energy as it melts

Endothermic Processes

• Heat of Vaporization = the energy a substance must absorb in order to change from LIQUID to GAS– Varies depending on

substance– Ex: I g of water absorbs

2258 J of energy when it vapors at 100 ° C.

Kinetic Theory• Word kinetic comes from the Greek word

meaning “to move”• Kinetic Theory of Matter says that all

particles of matter are in constant motion.– Gas-particles in CONSTANT, RANDOM motion– Liquid-particles “flow” to new locations– Solid-particles vibrate around a fixed location

Thermal Expansion • Occurs when particles of matter move

farther apart as the temperature increases– Gases expand more than liquids– Liquids expand more than solids

• Thermal expansion is used in glass thermometers– As the temperature increases, the alcohol in the

tube expands and its height increases so you can read the temperature.