14/01/2019 Describe…….

P1 1.3 States of Matter: Learning Objectives 14/01/2019 P1 1.3 States of Matter: Learning Objectives To know what the particle arrangement is in solids, liquids and gases. Describe the different amounts of energy that the particles have. Explain how energy is transferred by evaporation and condensation. Describe and explain the factors that affect the rate of evaporation and condensation.

Starter 14/01/2019 http://www.abpischools.org.uk/page/modules/solids-liquids-gases/slg2.cfm?coSiteNavigation_allTopic=1 Solids, liquids and gases Design a table and list examples of solids, liquids and gases. Draw the particle arrangement for a solid, liquid and gas.

Words – Solids, tiny particles, gases Kinetic theory 14/01/2019 The kinetic theory states that everything is made of _______ ________, and the arrangement and movement of the particles determine the properties of solids ______ and ______. Words – Solids, tiny particles, gases

Words – strong, close, vibrate, fixed Kinetic theory 14/01/2019 Kinetic theory is all about explaining the properties of solids, liquids and gases by looking at what the particles do. View animation SOLIDS In a solid the particles ______ around a _____ position. There is a ______ force of attraction between each particle and they are very _____ together. They usually cannot be compressed. Words – strong, close, vibrate, fixed

Words – fixed, collide, quickly, close, compressed, solids 14/01/2019 LIQUIDS GASES In a liquid the particles are _____ together but can move in any direction. They won’t keep a _____ shape like _____ do. The bonds between the particles are not as strong as a solid. Liquids can take the shape of a container. In a gas the particles are very far apart and move _____ in all directions. They often ______ with each other and because they are far apart they can be easily _______. Words – fixed, collide, quickly, close, compressed, solids

The main differences between the three states of matter. 14/01/2019 The main differences between the three states of matter. Flow Shape Volume Density Solid No Fixed Much higher than a gas Liquid Yes Fits container shape Gas Fits container Can be changed Low compared with a solid or liquid

Words – kinetic energy, fixed, bonds, move, solid, break. Changing state 14/01/2019 When a solid melts the particles _____ away from their _____ positions and _____ around. They have more _____ ______. A _______ takes in energy while it is melting but because the energy is being used to break the _____ between the particles the temperature does not change. This is demonstrated in the graph on the next page. Words – kinetic energy, fixed, bonds, move, solid, break.

Heating ice 14/01/2019 Temp/OC 150 100 50 -50 This flat line shows where energy is being used to push the particles further apart for evaporation This flat line shows where energy is being used to break bonds – this has to be done during melting Time/s

Cooling by Evaporation. 14/01/2019 The particles in a liquid or a gas have a range of different energies. The temperature of a substance is determined by the average kinetic energy of the particles. Heat can also be lost when water evaporates (this is how we cool off when we sweat): View animation This water will evaporate because the water molecules have enough energy to “escape” from the rest of the water. When they do so they will take heat with them. Evaporation has transferred energy away from the liquid.

Condensation Factors affecting evaporation and condensation. 14/01/2019 Condensation When a gas condenses to form a liquid, energy is released as the particles become closer together and form strong bonds. Factors affecting evaporation and condensation. Q) Evaporation will happen faster if: (discuss in pairs) The temperature is higher There is more surface area from which particles can escape. Air is moving over the surface of the liquid – this carries away any evaporated particles so they cannot condense back into a liquid again.

Practical Changing state 14/01/2019 Changing state Heat water using Bunsen burner, notice when steam leaves. What happens when the water boils? Switch off the Bunsen and hold a cold object above. What happens? A heating curve (refer to the practical sheet) Design a story about the life of a water molecule and how it changes state. Homeworkhttp://www.uvm.edu/~inquiryb/webquest/sp09/ndecaro/ http://www.abpischools.org.uk/res/coResourceImport/modules/solids-liquids-gases/fullscreenflash094c.cfm?flash=en-flash/launcher_movie.swf&title=Solids,+Liquids+and+Gases&version=6

Questions Why can gases be compressed, but not solids or liquids? 14/01/2019 Why can gases be compressed, but not solids or liquids? Explain the best weather for hanging washing out to dry. Explain how sweating helps to keep you cool. Sketch a graph to show the change in temperature as water is allowed to cool down. A* Explain in detail the shape of the graph you drew for Q 4. Exam feedback Evaporation from a liquid can happen at any temperature. When a liquid boils, evaporation is happening throughout the liquid and bubbles of gas form in the liquid. These are bubbles of the substance that is boiling, Not bubbles of air.