Is It Matter? • Circle the items that you believe are matter: • Table • Air • Glass • Sound • Light • Sand • Write your own definition of what matter is.
Is It Matter? • Circle the items that you believe are matter: • Table • Air • Glass • Sound • Light • Sand • Now lets fix that definition…
Matter: • Anything that has mass and take up space! • Properties of matter can be used to classify it…we will discuss these tomorrow!
Unit 1 The Nature of Matter 2011
Physical Properties • Help to identify a substance • Are readily observable • Color, hardness, density, boiling point, change of state etc.
Physical Properties Continued • Thermal Conductivity: the rate at which a substance transfers heat • Good conductor: metal • Poor conductor: Styrofoam • State: the physical form in which a substance exists. (solid, liquid, gas or plasma) • Solubility: the ability of a substance to dissolve in another substance. (ex. Flavored drink mix in water)
Physical Properties Continued Ductility: the ability of a substance to be pulled into a wire Malleability: the ability of a substance to be rolled or pounded into thin sheets
Physical Change • Cause changes to physical properties • Physical properties will change but the substance or type of matter will remain the SAME! • DO NOT result in the formation of a new substance
Examples of Physical Change • If you melt a block of ice, you still have H2O in the end. • If you break a bottle you still have glass. • Painting a piece of wood will not make it not be wood. • Melting, freezing, breaking, condensing, crushing, cutting and bending
Chemical Properties • Describe matters ability to change into new matter. • Can only be observed if the type of matter is changed • Characteristic Property: A property that is always the same no matter the size of the sample. These can be used to identify and classify a substance. • Examples: density and magnetism
Chemical Property Examples • Flammability: • will the object burn? • Reactivity • Will to substances react to form a new substance?
Difference between physical and chemical properties? • We can observe physical properties without changing the substance. We cannot observe a chemical property without changing the matter involved.
Chemical Change • A change that matter undergoes when it turns into a NEW substance – elements of the original substance are broken apart and rearranged to form a NEW substance • Chemical Changes ALWAYS result in the formation of a NEW substance with different properties than the original substance(s). • Chemical Changes are difficult to reverse (think of trying to unbake a cake)
Common Examples of Chemical Change: • Burning a log causes a chemical reaction that releases carbon dioxide • Placing an alka-seltza in water releases carbon dioxide bubbles • Exposing some metals to water and oxygen causes the formation of rust • Other processes that include chemical reaction: • Digestion • Respiration • Photosynthesis • Decomposition
Signs that a chemical change has occurred: • Change in color • Change in odor • Production of heat • Fizzing • Foaming • Sound or light being given off
Physical or Chemical?Property or Change? • A bike is left out in the rain and begins to rust • A match burns, leaving only a charred stick of wood • A copper wire is cut into 5 pieces • Flammability • An ice cube melts • Solubility • Gasoline burns in a running car
Physical or Chemical?Property or Change? • Water boils at 100 degrees Celsius • A silver tea set tarnishes over time • A water molecule gains enough energy to enter the vapor phase • Lemonade powder is soluble in water • Food coloring is added to cake icing to make it pink • Alka seltzer is put into water and bubbles form • NaOH + HCl NaCl + H2O