States of Matter • Solids – Have definite shape and volume. • Particles vibrate in place. • Tend to have high densities (>1 g/mL) [http://www.harcourtschool.com/glossary/science/images/gr4/solid4.jpg]
States of Matter • Liquids – Definite volume, but takes shape of container. • Particles slide past one another, but are always touching. • Densities tend to be near 1 g/mL [http://www.harcourtschool.com/glossary/science/images/gr4/liquid4.jpg]
States of Matter • Gases – No definite volume, or shape (can take shape of container). • Particles not touching, but randomly bounce off of one another. • Tend to have lowest densities (<< 1 g/mL) [http://www.harcourtschool.com/glossary/science/images/gr4/gas4.jpg]
States of Matter • Plasma – High temperature gas made of positive and negative particles. [http://www.cns-snc.ca/branches/Toronto/fusion/fusion_plasma.jpg]
States and Temperature • Temperature measures the kinetic energy of the particles in a substance. • Measured in Celsius (ºC) or Kelvin (K) [http://eml.ou.edu/Physics/module/thermal/flores/temp%20scales.GIF]
States and Temperature • Usually when objects are heated thermal expansion occurs and the volume increases. • The opposite occurs with water, as water freezes it expands. Click here for an expansion of metal video. Click here for an expansion of water video.
…then contraction of water under roads. Potholes form from the expansion…. [http://obr.gcnpublishing.com/articles/images/br02-04rdsci4.jpg]
Changes of State When matter changes states, temperature remains constant [http://www.bbc.co.uk/schools/ks3bitesize/science/images/sci_dia_22.gif] Click here for Changes of State Movie
[http://whatscookingamerica.net/Foto4/BoilingWater.bmp] Gas Liquid Kinetic Energy The highest temperature particles “escape” as a gas, leaving the cooler particles behind.
Changes of State • Melting Point – Temperature when a solid turns into a liquid. • For water this occurs at 0 ºC • Freezing occurs when a liquid turns into a solid. [http://wps.prenhall.com/wps/media/objects/476/488316/Instructor_Resources/Chapter_12/FG12_14.JPG]
Changes of State • Boiling Point – Temperature when liquid turns into a gas (vaporization). • For water this is 100.0 ºC Click here for Evaporation vs. Boiling [http://wps.prenhall.com/wps/media/objects/476/488316/Instructor_Resources/Chapter_12/FG12_14.JPG]
Changes of State Iron (Fe) When matter changes states, temperature remains constant Heating curves for different chemicals look the same, but the temperature scale changes!!! [http://www.bbc.co.uk/schools/ks3bitesize/science/images/sci_dia_22.gif]