Unit 2 Chemistry

Lesson 1 States of Matter

Essential Questions:

1.) How do you describe a solid?

2.) How do you describe a liquid?

3.) How do you describe a gas?

How do you describe a solid?

A state of matter with a definite Solid

shape and volume A solid does not take the shape of its

container

The apple’s shape and size is different than the bowl’s shape and size. If you put the apple on the table its shape and size will not change because it is a solid.

Particles In A Solid

They are packed closely together. Each particle is fixed in one position. The particles vibrate slightly.

Types of Solids

Solids that are made of Crystalline solids

crystals. The particles form

a repeating pattern. The

solid can melt at a

certain temperature.

Salt, sugar and snow are crystalline solids.

A solid where the particles Amorphous solids

do not form a regular

pattern. The solid does

not melt at a certain

temperature.

Glass and plastic are examples of amorphous solids.

Types of SolidsUse the Venn diagram to compare the characteristics of amorphous and crystalline solids.

How do you describe a liquid?

A state of matter that has a Liquid

definite volume but no

definite shape A liquid can take the shape of its container

The ice tea has the same volume in both containers. However, the shape of the ice tea changes in each container.

Particles In A Liquid

They are packed together. They move around freely but still touch.

Properties of Liquids

An inward force or pull Surface tension

among the molecules in

a liquid that brings the

molecules on the surface

closer. Water beads up on the surface of the leaves because the water molecules attract one another.

A liquid’s resistance to Viscosity

flowing that depends

on the size, shape and

attraction of the particles

Honey is an example of a liquid with very high viscosity.

How do you describe a gas?

A state of matter that does not Gas

have a definite shape or volume

When you use helium to fill balloons, the gas particles expand to fill the balloon. It takes the shape and volume of the balloon.

Particles In A Gas

They move in all directions. Gas particles will spread apart and fill

the container.

Volume and Gas

The volume of a gas is the same volume as its container. The gas particles spread a part and fill the space.

Helium gas can be pressed together tightly to fit into a tank. The gas expands to fill the balloon which has a greater volume than the tank.

Pressure and Gas

Gas pressure is caused by the gas particles pushing on the walls of the container.

The pressure is greater on the inside of the balloon. The gas particles are hitting the inner surface more often than the particles on the outside of the balloon.

Temperature and Gas

The faster the particles are moving, the greater their energy and the higher the temperature.

Temperature of a GasWhy do hot gas particles move faster than cold gas particles?

A propane burner is used to heat the air inside a hot air balloon. Once the temperature is hot enough, the balloon will start to rise.