COMMON PROPERTIES OF MATTER All matter has- Mass- Weight- Volume (takes up space)- Shape
PROPERTIES OF MATTER Brittleness - the property of matter that is how easily the substance breaks or shatters when force is applied to it. Elasticity - the ability of a substance to be stretched and then to return to its original shape. Hardness - property of matter that determines how easily the substance can be scratched.
PROPERTIES OF METALS Ductility - property of a metal in which it can be stretched without breaking. Malleability - the property of a metal that allows it to be hammered, rolled, pressed or forged. Conductivity – property of a metal that allows it to conduct electricity Magnetism – the property of a metal in which it is attracted to a magnet
Types of Science QuestionsKNOWLEDGE What is the freezing point of water?COMPREHENSION Explain the difference between physical and chemical change?ANALYSIS Which is a physical change and why? Sugar dissolved in water Burning paper turning into ashSYNTHESIS In cold countries salt is strewn on icy roads. Explain the scientific reasoning behind this.
What is a physical change?Give a real life exampleof a physical change?
Requires energy from environment Cooling Process Releases energy to environment Warming Process
Changes in States of MatterDepositionEvaporationSolidification/FreezingMeltingSublimationCondensation
Time- Temperature Graph for Water When will the temperature of the water rise above 100 degrees Celsius? 100 Why is the slope of the graph flat (noTemperature (degrees Celsius) temperature change) at 100 degrees even though the stove is still on? What is true for the ice-water mixture when the temperature began to rise? Why did temperature increase at a constant rate? 0 Why is the slope of the graph flat (no temperature change) at 0 degrees? Time (minutes)
Time- Temperature Graph for Water Once the water is in the gas phase, additional heat input raises the temperature of the water vapor Note: greater energy is needed to vaporize water than to melt it. WHY? 100 As the liquid begins to boil. AdditionalTemperature (degrees Celsius) input of heat energy does not raise the temperature of the water, rather it is used to break water bonds. i.e. phase change. As the temp approaches boiling point, the KE of the molecules is sufficient to allow the separation of molecules into the gas phase. Once the water is in a liquid phase, increasing the amount of heat input raises the temp of the liquid water. As the ice begins to melt, additional heat energy does not raise the temperature of the water, but loosens the bonds changing ice to water. i.e. phase change – melting. 0 As the temp approaches melting point temperature, the KE of the water molecules increases loosening the bonds between water molecules. Time (minutes)
Phase Change- ___________ energy from stove = energy required for phase change ______ states of ______ temperature change Matter _____ states of Matter Energy from stove causes increased ____E and increased ___________ Phase Change- _______________ states ofMatter energy from stove = energy required for phase change ____ temperature change Energy from stove causes increased ___E and increased _____________
Phase Change- Vaporization energy from stove = energy required for phase change Two states of Matter No temperature change One state of Matter Energy from stove causes increased KE and increased Temperature Phase Change- MeltingTwo states of Matter energy from stove = energy required for phase change No temperature change Energy from stove causes increased KE and increased Temperature
Boiling point temperature at which a liquid changes to a gas
Melting point the temperature at which a substance changes from a solid to a liquid.
Solidification (freezing) changing of a liquid to a solid
Salt on snow-covered roads? If you live in an area with a cold and icy winter, you have probably experienced salt on sidewalks and roads, used to melt the ice and snow and keep it from refreezing. Salt is also used to make homemade ice cream. In both cases, the salt works by lowering the melting or freezing point of water. The effect is termed freezing point depression So, when you add a salt to ice with a little bit of water, the salt lowers the freezing point of the water, keeping it from re- freezing as easily and helping to melt the rest of the ice.
Sublimation the changing of a solid directly to a gasExampleDry ice is solid carbon dioxide. At room temperature andpressure, it sublimates into carbon dioxide vapor.
Deposition this is a phase change from a gas directly to a solid Dry Ice The Iodine Test Iodine test: http://www.youtube.com/watch?v=4fAOI6BeMZY
Evaporation changing of a liquid to a vapor at any temperature below its boiling point.
NATURE OF THE SUBSTANCE Alcohol Water Oil Why does alcohol evaporate faster?Both alcohol and water have hydrogen molecules that bond. However, thebonds in alcohol molecules are weaker which allows for alcohol to evaporatefaster.
2. Copy and complete the following sentences using the words below: Solution solvent solute saliva dissolves exposed salivaThe candy dissolves in the ……………………..in your mouthto form a liquid …………………………..Solutions contain two parts, a ………………….. and a……………………………….The solvent is …………………….. and the solute is the candy.The solute……………………….. by spreading out evenlythroughout the solvent.The candy can quickly dissolve when it is ……………… tochewing and stirred by moving it around with the tongue.
Ms Pommeroy cooks rice in a pressure cooker. Why? A pressure cooker is a sealed pot. Steam trapped inside the pot under pressure allows the temperature to rise beyond what it could reach normally in a traditional uncovered pot. As the pressure inside the cooker increases, the boiling point of the water inside increases as well. This causes the food to cook at a higher temperature, which cooks it faster.
CHEMICAL CHANGE PHYSICAL CHANGE In a chemical change where there is a A physical change in a substance doesntchemical reaction, a new substance is change what the substance is.formed and energy is either given off orabsorbed.If a piece of paper is burned, it is broken up For example, if a piece of paper is cut up intointo different substances that are not paper. small pieces it still is paper. This would be a physical change in the shape and size of the paper.Chemical changes cannot be reversed with Physical changes can be reversed.the substance changed back withoutextraordinary means, if at all.If one made a recipe for a cake with flour, If one decided to mix sugar/salt into waterwater, sugar and other ingredients and to make sugar/salty water, this would be abaked them together, it would take physical change as the water could be leftextraordinary means to separate the various out to evaporate and the sugar/salt crystalsingredients out to their original form. would remain. Note: remember salt is sodium chloride (NaCl)
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