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Unit 2 1.How do you know matter is made of particles? 2.What are the particles called? 3.What are the particles doing ? 4.What happens to the particles during a phase change?
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Unit 2 What are some everyday experiences that show matter is composed of particles—write down your ideas to share with the class. What do you think the name of these particles is?
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Unit 2 1.Proof matter is made of particles ex: blow air into a balloon and it expands pump up a basketball wind air pressure (yardstick demo) 2.Particles of matter called: ATOMS
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Unit 2 Matter is made of small particles called atoms and can exist in four forms or states: 1.Solid 2.Liquid 3.Gas 4.Plasma Let’s explore and describe each phase
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Unit 2 Solid phase: 1.Particles are as close together as possible. 2.retains a fixed volume and shape rigid - particles locked into place 3.not easily compressible because of little free space between particles 4.does not flow easily 5.rigid - particles cannot move/slide past one another
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Unit 2 Arrangement of particles in the solid phase
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Unit 2 Liquid phase 1.assumes the shape of the part of the container which it occupies 2.particles can move/slide past one another 3.not easily compressible because of little free space between particles 4.flows easily because particles can move/slide past one another
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Unit 2 Arrangement of particles in the liquid phase
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Unit 2 Gas phase 1.Particles are widely separated 2.assumes the shape and volume of its container 3.particles can move past one another 4.Compressible, reason: lots of free space between particles 5.flows easily reason: particles can move past one another
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Unit 2 Arrangement of gas particles
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Unit 2 Plasma phase 1.Similar to gas phase but particles are charged 2.Electrons have been removed from atom by addition of energy (heat or electricity) 3.Most abundant phase of matter in the universe 4.Example would be fluorescent lights
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Unit 2 Plasma link https://www.youtube.com/watch?v=AVEGJZx glIg
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Unit 2 Phase change lab. Follow instructions in your packet.
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Unit 2 Post phase change lab—cooling curve A BC D What did you observe in tt at each letter?
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Unit 2 Post phase change lab—cooling curve A = only liquid BC D
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Unit 2 Post phase change lab—cooling curve A = only liquid B = first solidC D
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Unit 2 Post phase change lab—cooling curve A = only liquid B = first solidC = last liq D
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Unit 2 Post phase change lab—cooling curve A = only liquid B = first solidC = last liq D = only solid
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Unit 2 Post phase change lab—cooling curve A = only liquid B = first solidC = last liq D = only solid What do we say is happening to subst. between B and C?
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Unit 2 a.substance was cooling (losing heat) entire time. b.Substance should decrease temperature entire time. Problem: if substance was cooling why did the temperature stop going down?
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Unit 2 Material was liquid to begin with, then began to change to solid—called PHASE CHANGE ----- this phase change is called: Freezing or Heat of Solidification -----this happened between letters B---C ----- on what is called the plateau (flat portion) -----flat = no change in temperature -----this is then the Freezing Point of the subst. -----but was cooling entire time!! Losing heat!
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Unit 2 Let’s find the pattern! What happened between pts: A---B substance was Cooling lose heat temp decreases all liquid
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Unit 2 B---C cooling lose heat freezing or phase change (solid—liq) Temp constant—Why?? this is science!! Good labs pose more questions than they answer, it leads to more labs, it leads us to the truth. We will find out in a later lab
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Unit 2 C---D cooling lose heat temp decreases all solid
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Unit 2 Phase change lab—heating curve H FG E Now you fill in what would be seen at each letter
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Unit 2 E = all solid F = first liquid appears G = last solid gone H = all liquid The material was being warmed (Heated) the entire time. Between F—G the substance changed phase from solid to liquid Called: Melting (heat of fusion) Therefore the melting point was = plateau
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Unit 2 See anything funny????? That’s right, melting and freezing pts are the same temperature!!!
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Unit 2 So to melt something heat needs to be added To freeze something heat needs to be removed What is happening to the particles? When energy added particles move faster When energy removed particles move slower Called: Kinetic Molecular Theory (KMT)
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Unit 2 KMT states all matter is made of particles in constant, endless motion. PhaseType of motion Solidvibrate Liquidvibrate, rotate, translate Gasvibrate, rotate, translate
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Unit 2 Motion of particles link: http://www.kentchemistry.com/links/Matter/ phases.htm
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Unit 2 Two more terms you must know: Viscosity and Thermal expansion Viscosity: ability to flow or pour. solids = no viscosity liquids = high viscosity gases = high viscosity
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Unit 2 Thermal expansion: KMT states particles move faster as heat (temperature) increases. Therefore the particles will get farther apart. The volume of the sample will increase That’s why a balloon will shrink in the freezer and expand in the oven! I guess density will change as well????
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Unit 2 Thermal expansion: If a sample is warmed, what will happen to the density ? Answer choice-----INCREASE or DECREASE??
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Unit 2 Complete synthesis of slime lab
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Unit 2 Post synthesis of slime lab
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Unit 2 Lab: Qualitative description of gas laws
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Unit 2 Post lab gas laws
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Unit 2 Complete boyle’s law lab
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Unit 2 Post Boyle’s law lab
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Unit 2 Complete worksheet on gas laws
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Unit 2 Complete lab on physical and chemical properties and changes
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Unit 2 Physical property: A characteristic that can be measured or observed without changing the nature of the sample. Ex: color, mass, density, odor, volume
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Unit 2 Physical change = phase change! Material does not change Distance between particles changes! Solid------liquid------gas Close---- farther---farthest
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Unit 2 Chemical change: Only observed if two or more substances mixed together. Evidence = change in color change in temperature formation of gas (bubbles, odor) formation of precipitate (solid from liquid)
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Unit 2
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