Matter Matter and Particles All matter The state

Matter

Matter and Particles • All matter • The state of a substance

The Phases of Matter • There are FOUR states of matter: 1. Solid 2. Liquid – 3. Gas – 4. Plasma –

Solid Particles • In a solid, the particles are __________. They vibrate in place and the attraction between them is _____. This causes the particles to lock together.

Liquid Particles • In a liquid, the particles _______________. This allows the particles to flow around and over each other. Liquids assume _______________. • Liquids can also be called ____– which means a ______________

Gas Particles • In a gas, the particles ____________________________. That’s why a gas will spread out in all directions – filling up a balloon, a room, or the atmosphere.

Melting: From Solid to Liquid • Melting • The temperature at which a solid melts is called its _______. The melting point is different for different solids. For ice, it is 0 o. C or 32 o. F.

Melting and the Particles • As you heat a solid, the particles in that solid will begin to move_______________. • Eventually the motion of the particles will become great enough to overcome the attraction that locks the particles together as a solid. When that happens, the solid becomes a liquid because the particles start to flow.

Freezing: From Liquid to Solid • Freezing • The temperature at which a liquid freezes is called its _______. The freezing point for different solids is different. For water, it is 0 o. C or 32 o. F.

Freezing and the Particles • If you cool a liquid, the particles will begin to ______________. • Eventually the motion of the particles will slow to the point where they cannot overcome the attraction between them. When that happens, the particles will lock together and become a solid.

Vaporization: From Liquid to Gas • Vaporization • The temperature at which water changes from a liquid state to a gaseous state is 100 o. C or 212 o. F. This is known as its _______.

Vaporization and the Particles • As a substance is heated, its particles begin to _______________. • During vaporization, the fastest particles are able to overcome the attraction of the particles around them and break free completely. These escaped particles become a gas (ex: water vapor).

Vaporization vs. Evaporation • Vaporization refers to _____________________________. • _______ is a specific type of vaporization which occurs at temperatures below the boiling point of a liquid. • So vaporization includes ______________.

Vaporization vs. Evaporation • Evaporation occurs _____________, but vaporization could happen _____________when a liquid is boiling. • Think about water evaporating from a puddle vs water boiling in a pot.

Vaporization: Solid to Gas • Sublimation • This is a result of vapor pressure and temperature relationships. (Examples include dry ice and freeze drying food. )

Condensation: From Gas to Liquid • Condensation • The temperature at which a gas condenses is called its condensation point. For water vapor, it is 100 o. C or 212 o. F.

Condensation: From Gas to Liquid • If you cool a gas, the particles will begin to ______________. • Eventually the motion of the particles will slow to the point where they cannot overcome the attraction between them. When that happens, the particles will lock together and become a liquid.

Physical Properties • A physical property of matter • Some physical properties are color, odor, mass, volume, magnetism, ability to conduct current, strength, flexibility, hardness, and texture. • Ex – Will your books fit into you backpack? You are using the physical property of volume. 19

Physical Properties • Thermal conductivity – • Ex. Styrofoam is a poor conductor. • State of Matter – • (ex: ice, water vapor) • Density – • (ex: Lead is very dense so it is used to make an anchor. ) 20

Physical Properties • Solubility – • (ex: Kool-Aid power dissolves is water. ) Sometimes you can increase solubility by changing the temperature. • Ductility – • (ex: Copper is often used to make wiring because it is ductile. ) • Malleability – • (ex: Aluminum can be rolled into sheets to make foil. ) 21

Physical Changes • A physical change is • Ex. A piece of silver is pounded and molded into a heart-shaped pendent. (it is still silver) • Ex. – changing from a liquid to a solid (or any phase change) • Ex. – crushing an Aluminum can. It is still aluminum, just the shape has changed. • Ex – Sawdust – it is still wood – only in smaller pieces. 22

Chemical Properties • Chemical properties describe matter based on its ____________________________________ (in the form of a chemical reaction). • Chemical changes occur when • Ex. – burning wood, tarnishing, and rusting 23

Chemical Properties • Flammability – • (wood can burn, but ash and smoke cannot) • Reactivity – is the ability of two or more substances to __________________ • Chemical reactions involve two main kinds of changes that you can observe – __________________ 24

Physical Properties vs. Chemical Properties • A nail will bend – • A nail will rust – ______________________(iron is reacting with oxygen to make iron oxide - ______) • Alcohol will evaporate – • Alcohol will burn – ________– it is not alcohol any more. 25

How do I know that a chemical change is taking place? • There will be a change is odor, color, heat will be either absorbed or released, the substance will bubble or fizz, light or sound may be given off. • Ex. • • • 26

Changes in Energy • As matter changes, it can either absorb or release energy. A change in energy occurs during a chemical reaction. • An endothermic reaction • Many endothermic reactions occur when heat is constantly added. (Ex: egg frying) In other words…they need energy to keep going. 27

Changes in Energy • An exothermic reaction • After an exothermic reaction, the products have less energy than the reactants. (Ex: the burning of fuel) • The reaction between fuel and oxygen in an airplane engine releases energy, mostly in the form of heat. The expansion and movement of the gases out of the plane exerts a force that moves the plane forward. 28

Can physical and chemical changes be reversed? • Physical changes are __________. You can melt ice and then freeze it again. • Chemical changed are _________. When a firework explodes it would be almost impossible to put the materials back together. 29