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Substance Substance is a type of material with a fixed composition A substance can be either an element or a compound Examples: Water, salt, helium

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Substance All substances are built from atoms

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Substance Element substance with atoms that are all alike Examples are Zinc, copper, carbon Elements are found on the periodic table

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Substance Compounds substance formed by two or more elements in a fixed portion Water is a compound always made of one oxygen and two hydrogens

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Mixtures Mixture is a material made up of two or more substances that can be easily separated by physical means Mixtures do not always have to have same proportions.

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Mixtures Heterogeneous Mixtures are mixtures in which different materials can be distinguished easily Does not always mean it is easy to see just easy to separate by physical means

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Mixtures Homogeneous Mixtures mixtures that contain two or more gaseous, liquid or solid substances blended evenly throughout the entire mixture. Solutions are another name for homogeneous mixtures

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Mixtures Colloid a type of mixture with particles that are larger then those in solutions but not heavy enough to settle out. Colloids can be determined because their particles are large enough to scatter light, this is called the Tyndall effect.

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Mixtures Suspension heterogeneous mixture containing a liquid in which visible particles settle. Example pond water, some mud particles settle out and the water clears

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Physical Properties Physical properties any characteristic of a material that you can observe without changing the identity of the substances that make up the material

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Physical Properties Appearance what does it look like Behavior how does it act in different situations Is it rough or smooth, bounce or roll

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Physical Change Physical change is a change in size, shape, or state of matter. The substance does not change just the appearance and behavior Example: freeze, boil, evaporate or condense

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Physical Change Distillation is the process for separating substances in a mixture by evaporating a liquid and recondensing its vapor Can be used to get other materials out of water

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Chemical Properties Chemical property is a characteristic of a substance that indicates whether it can undergo a certain chemical change Burning something causes a chemical change Rusting is a chemical change

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Chemical Change A chemical change is when a substance undergoes a change in which a new material is formed. When Iron oxidizes it forms rust and changes color Substances can be separated using chemical changes A chemical reaction can turn tarnished materials back into what they were originally

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Law of Conservation of Mass The law of conservation of mass says that the mass of all substances that are present before a chemical change equals the mass of all substances that remain after the change.

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Solids, Liquids and gases Draw picture of the particles of solids, liquids and gases Label the movement of particles of each Label how it is shaped

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Kinetic Theory Kinetic Theory is an explanation of how particles in matter behave Three assumptions 1. All matter is composed of small particles 2. These particles are in constant, random motion 3. These particles are colliding with each other and the walls of their containers

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Heating and Cooling Melting point the point at which a solid begins to liquefy Heat of fusion the amount of energy required to change a substance from the solid phase to the liquid phase at its melting point

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Heating and Cooling Boiling point is the temperature at which the pressure of the vapor in the liquid is equal to the external pressure acting on the surface of the liquid Heat of vaporization is the amount of energy required for the liquid at its boiling point to become a gas.

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Heating and Cooling Draw heating and cooling curves and label heat of fusion and heat of vaporization.

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Diffusion Diffusion is the spreading of particles throughout a given volume until they are uniformly distributed. The more dense a gas is the longer its diffusion rate

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Plasma Plasma is matter consisting of positively and negatively charged particles. The number of positively charged particles equals the number of negatively charge particles so the overall charge is neutral. Stars, sun, lightning bolts, neon and fluorescent bulbs are all things consisting of plasma Scientist estimate that much of the matter in the universe is plasma.

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Thermal Expansion Thermal expansion is an increase in the size of a substance when the temperature is increased. Solid thermal expansion bridge Liquid thermal expansion liquid in a thermometer Gas thermal expansion hot air balloons

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Water and thermal expansion Why does water not follow the rules for thermal expansion?

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Unusual Substances Amorphous Solids Plastics and glass They melt over a range of temperatures not a specific melting point Liquid Crystals These are used to make liquid crystal displays (LCD)

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Properties of Fluids Buoyancy is the ability of a fluid to exert an upward force on an object immersed in it If the weight of the object is equal to the buoyant force the object will float.

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Archimedes Principle When an object is placed in water, the object will push the water out of the way as it begins to sink. It will stop when the weight of the water displaced equals the objects weight

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Density If an object is more dense then the fluid it is in it will sink If an object is less dense then the fluid it is in it will float

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Pascals Principle Pascals Principle says that pressure applied to a fluid is transmitted throughout the fluid Example toothpaste tube

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Bernoullis Principle Bernoullis Principle says that as the velocity of a fluid increases, the pressure exerted by the fluid decreases Paper example

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Viscosity the resistance to flow by a fluid Syrup has a high viscosity, flows slowly Water has a low viscosity, flows quickly

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Behavior of Gases Pressure is force exerted per unit area Pressure is measured in a unit called pascal (Pa). Earths atmosphere has pressure exerting all around us.