States of Matter. Essential Question: How does the movement of atoms and molecules relate to matter s different phases?

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1 States of Matter Essential Question: How does the movement of atoms and molecules relate to matter s different phases? These notes come from pages 60 to 73 in your Physical Science Textbook

2 All Matter Is Made of Ultra Tiny Particles Called Atoms and Molecules. Atoms and molecules are in constant. This motion is called Thermal. When these particles gain heat, their motion and likewise, when they heat, their motion. Molecules with a lot of motion or tend to move apart, while those with less or tend to move.

3 Matter has 4 Common States (Phases) They have a definite shape and volume Liquids They have a definite but can change. Gases Change both and. Have no definite shape or volume. The particles are broken apart.

4 SOLIDS The in a solid are very close together. Crystalline solids the atoms or molecules are arranged in repeating patterns of rows. (iron, diamond, ice) Amorphous solids there is no organized pattern to the particles in this type of solid. (Most all solids are amorphous.)

5 Liquids A liquid will take the of whatever container it is in. The are further apart than those in a and can slide past each other easily. Unlike a gas, the volume remains the same no matter how large the.

6 Liquids Have Two Important Properties. tension the tendency of the particles at the of a liquid to have a greater force of attraction downward and side-to-side than the particles in the liquid. - a liquid s resistance to flow.

7 Gases The or in a gas have enough energy to break completely away from each other. There is a lot of empty between the particles. Because of this, can be compressed.

8 Gas under Pressure The atoms and molecules in a gas have lots of energy and very little for each other, thus they can spread out in all and have lots of space between them. This property makes gas compressible or able to respond to. This leads to the discussion of two very important laws regarding the behavior of.

9 BOYLE S LAW For a fixed amount of gas at a constant temperature, the volume of the gas increases as its pressure. Likewise, the volume of a gas as its pressure increases. (See figure 10 on page 65) How does Boyle s law explain why weather balloons are under inflated when launched?

10 CHARLES S LAW For a fixed amount of gas at a pressure, the of the gas as the temperature increases. Likewise, the volume of gas as temperature. (See figure 11 on page 66) Without using numbers, sketch two graphs that would illustrate Boyle s and Charles s laws.

11 volume Your graphs should look like these v olume temperature pressure

12 Plasmas Scientists estimate that more than 99% of the known matter in the is in the form of plasma. This includes the sun and all other stars. Plasma Properties: Conducts electric current (gases do not) Is affected by electric and fields Natural plasmas are found in lightning, fire, the aurora borealis, and the aurora. Artificial plasmas, found in fluorescent lights and plasma balls, are created by passing electric current through gases.

13 Plasma Ball

14 Changes of State A change of state is the conversion of a from one physical to another. All changes of state are changes. During a change of state, the of a substance changes. This, in turn will mean a change to the of its particles. (atoms and molecules) We have stated earlier what happens when energy is added or taken away. Recap that here: Energy increases particles move faster and spread apart Energy decreases particles move slower and move closer together.

15 The temperature of a substance is simply a measure of the of its particles! A transfer of energy known as heat, causes the temperature of a substance to change, which can lead to a of state.

16 Use your own words to describe the known changes of state below: Melting solid to liquid (melting points vary widely) Freezing liquid to solid (freezing and melting occur at the same temperature in a substance!) Vaporization liquid to gas Condensation gas to liquid (the attraction of the molecules overcomes their motion so they begin to clump together) Sublimation solid to gas (particles must move from being very tightly packed to very spread apart)

17 Endothermic and Exothermic Reactions Endothermic energy is absorbed into the changing substance. It should feel to the touch. For example when ice melts, it absorbs energy from the warmer air around it. That energy goes into the particles in the ice, causing their motion to and the particles to move apart. Exothermic the substance loses, and should feel to the touch. For example, when water freezes, it loses energy to the colder air around it, causing the in the water to slower and come.

18 A Graphic Summary on Change of State. See page 73 for a similar version