Solids, Liquids, and Gases

Lecture: States of Matter

Solids, Liquids, and Gases

There are four states of matter in the universe.

1. Solids

2. Liquids

3. Gases

4. Plasma (Matter which makes-up the stars)

Solids, Liquids, and Gases

Physical versus Chemical Properties

A Physical Property is a characteristic of a pure substance that can be observed without changing it into another substance.

Examples of physical properties are melting temperature, color, hardness, texture, ability to be dissolved, etc…

Solids, Liquids, and Gases

Physical versus Chemical Properties

A Chemical Property is a characteristic of a pure substance that describes its ability to change into different substances.

Examples of chemical properties are is the substance flammable, does it react in the presence of certain chemicals, etc..

Solids, Liquids, and Gases - States of Matter

Solids

A fixed, closely packed arrangement of particles causes a solid to have a definite shape and volume.

Solids, Liquids, and Gases

Solids

Solids that are made up of crystals are called crystalline solids.

In amorphous solids, the particles are not arranged in a regular pattern.

- States of Matter

Solids, Liquids, and Gases

Liquids

Because its particles are free to move, a liquid has no definite shape. However, it does have a definite volume.

- States of Matter

Solids, Liquids, and Gases

Gases

As they move, gas particles spread apart, filling all the space available. Thus, a gas has neither definite shape nor definite volume.

- States of Matter

Solids, Liquids, and Gases

Changes Between Solid and Liquid

The change in state from a solid to a liquid is called melting.

- Changes of State

Solids, Liquids, and Gases

Changes Between Solid and Liquid

The change of state from liquid to solid is called freezing.

- Changes of State

Solids, Liquids, and Gases

Changes Between Solid and Gas

The change in state from a solid to a gas is called sublimation.

The change in state from a gas to a solid is called deposition.

Solids, Liquids, and Gases

Temperature and Changes of State

A beaker of ice at –10ºC was slowly heated to 110ºC. The changes in the temperature of the water over time were recorded. The data were plotted on the graph shown here.

- Changes of State

Solids, Liquids, and Gases

Temperature and Changes of State

Temperature (ºC) on the y-axis, time (minutes) on the x-axis

Reading Graphs:

What two variables are plotted on the graph?

- Changes of State

Solids, Liquids, and Gases

Temperature and Changes of State

The temperature is rising from 0ºC to 100ºC.

Reading Graphs:

What is happening to the temperature of the water during segment C of the graph?

- Changes of State

Solids, Liquids, and Gases

Temperature and Changes of State

Segment B: melting point of ice; segment D: boiling point of water

Interpreting Data:

What does the temperature value for segment B represent? For segment D?

- Changes of State

Solids, Liquids, and Gases

Temperature and Changes of State

Change from solid to liquid; change from liquid to gas

Drawing Conclusions:

What change of state is occurring during segment B of the graph? For segment D?

- Changes of State

Solids, Liquids, and Gases

Temperature and Changes of State

Water molecules in segment E have more thermal energy because they are at a higher temperature.

Inferring:

In which segment, A or E, do the water molecules have more thermal energy? Explain your reasoning.

- Changes of State