Solid + Energy = ? When energy is added to solids, they become liquids! Examples?
Liquid + Energy = ? When energy is added to liquids, they become gases! What examples can you think of?
Changing States There are several names for matter changing states: State change Phase change Physical change
So, did we get something new? Ice cream and melted ice cream? Chocolate and melted chocolate? Ice, water, and water vapor? Steel and molten steel?
Physical Properties A characteristic of a substance that can be observed or measured without changing the substance Ex: shape, color, length, mass, volume, density, odor, texture, states of matter, melting and boiling point
Weight measure the gravitational force exerted on an object. Can be expressed in either newtons and/or pounds. Inertia the tendency of all objects to resist any change in motion. Mass is a measure of inertia.
Measuring Volume Volume = length x width x height (cm³) Look at the meniscus when measuring liquid in a graduated cylinders, beakers, measuring cups, etc... Displacment: measure the liquid Put irregular object in the container Measure liquid Subtract Finish – Start = volume
Pretend you can only feel the object in the bag. Can you guess what it is? Some Physical Properties: round smooth hard about the size of your fist Click here for mystery object. ?
Thermal Density Solubility State Ductility Malleability
Physical Changes Physical Changes do not change the composition. The substance may look different but the identity does not change Grinding Cutting Coloring Dissolving Changes in the state ***Can usually be changed back***
Chemical Properties Any characteristic that gives a substance the ability to undergo a change that results in a new substance Ex: Flammability, Ability to react with: oxygen, electricity, light, water, heat etc
Chemical Properties The ability to change into a new matter with different properties.
¿What’s the difference? Physical Properties - Can be measured or observed. Do NOT change the chemical nature of matter properties. Chemical Properties –Describes how something will react. DO change the chemical nature of matter properties
Chemical Changes Chemical Changes are changes in the identity of a substance due to the chemical properties Bubbles Color change (why did it change color?) Production of Heat or Cold Production of Light Production of Smoke Formation of a new substance Cannot usually be changed back
Make a T chart in your spiral Classify each of the following as physical or chemical Gas productionTarnishing SouringExpanding CoolingHeating DigestingRusting DentingSqueezing SawingLight production BurningDissolving StretchingRotting CuttingChange of temperature MeltingFreezing New substanceMixing DryingContracting
Make a T chart in your spiral Classify each of the following as physical or chemical CGas productionCTarnishing CSouringPExpanding PCoolingPHeating CDigestingCRusting PDentingPSqueezing PSawingCLight production CBurningPDissolving PStretchingCRotting PCuttingCChange of temperature PMeltingPFreezing CNew substancePMixing PDryingPContracting
Changes in Energy Endothermic – energy is absorbed from the surroundings – temperature decreases Ex: Ice Melting Exothermic – energy is released into the surroundings – temperature increases water freezing
Classify the Following as Endothermic or Exothermic Burning a match Exothermic Photosynthesis Endothermic Condensation on a window Exothermic
Classify the Following as Endothermic or Exothermic Candle Flame flickering Exothermic Evaporation of water Endothermic Melting an ice cream cone Endothermic
Classify the Following as Endothermic or Exothermic Cooking an Egg Endothermic Freezing dinner Exothermic Baking Bread Endothermic
Classify the Following as Endothermic or Exothermic Exothermic Endothermic
Rate of Reaction Reactions can vary in speed Changes in Size, Concentration and Temperature can change reaction speed Catalysts speed up reactions Inhibitors slow them down
Law of Conservation of Mass Matter cannot be created or destroyed In other words, the mass you end up with is always the same as what you start with Then where does the mass go sometimes? Ex: Wood for a campfire