Changes in Matter

Chapter 3 sections 1 and 3

Solid•Definite Shape and Definite Volume.

Particles in a solid

•Atoms and/or molecules are packed closely together and slightly vibrate.

Types of solids

• Crystalline solid: Arranged in a crystal-like, repeating pattern.

• All have a distinct melting point.

Types of solids cont….

• Amorphic Solid: Particles are arranged in an irregular or random pattern.

• Don’t have a distinct melting point.

• Example: Glass, plastic, rubber

Liquids

• Takes the shape of the container that it’s in.

Particles in a Liquid• Atoms and/or molecules are

loosely packed together.

Suspension

• A mixture where particles can be seen and easily separated.

• Examples: Milk, salad dressing and muddy water

Viscosity

The resistance of a liquid to flow.The higher the viscosity, the slower it will flow.Usually amorphic solids.

Water

• Surface tension: Molecules on the surface are only affected by those below the surface, thus causing drops of liquid to be spheres.

•TAKE OUT YOUR OOBLECK LAB

Gases

• Have no definite shape and no definite volume.

• Very compressible.

Particles in a gas

• Particles are not touching, therefore the Intermolecular forces are broken.

• Movement is random and independent of each other.

Boyle’s Law

• At a constant temperature, if the pressure of a gas increases its volume decreases.

Graph of Boyle’s Law

Pressure and Temperature of gases

• When the temperature of a gas increases its pressure increases and when temperature decreases pressure decreases.

Charles' Law

• When temperature of a gas increases its volume increases.

• In other words, gases expand as they heat up and condense as they cool down.

Energy and State Change

• When a substance changes state:

• Solid liquid gas = gaining energy

• Gas liquid solid = loses energy

Measuring Gases

• Temperature: the measure of the motion (kinetic energy) of the particles of a substance.

Measuring Gases Cont…

• Pressure of a gas: The measure of the outward force divided by the surface area of the container.

Increased Temperature

Increased average velocity of gas particles

Increased number of collisions with walls of container

Increased Force per collision.

Inside pressure is greater than external pressure.

Container expands Increased Volume

Initial increase in pressure force ÷ area of container

Take out your Hot Air Balloons Lab and write down

the Purpose:

To Learn how the volume of a gas

changes with temperature.