  Features of all matter that can be observed and measured without changing the chemical composition of the substance  State of matter  Volume  Mass  Weight  Density  Many, many more Physical Properties

  Physical properties that will change depending on the amount or size of a substance:  Volume – the amount of space an object takes up  Mass – the amount of matter an object has  Weight – a measure of the force, or pull, on objects due to gravity  On Earth, mass and weight are equal. However, on the moon mass and weight would be different because the Moon’s gravity is less than Earth’s Size-dependent properties

  1. Would your mass be different on the Moon?  No. Mass is the amount of matter you have. That would not change.  2. Would your weight be different on the moon?  Yes  3. Would you weigh more or less?  You would weigh less because the Moon’s gravity is less than Earth’s gravity Assessment Time

  Physical properties that stay the same no matter how much of a substance there is:  Color, taste, odor  State of matter (solid, liquid, gas)  Malleability – can be hammered into thin sheets  Brittleness – break if they are hammered  Ductility – can be drawn into a wire without breaking  Conductivity – heat and electricity move easily through them Size-independent properties

  Take the copper wire out of the bag  Observe it.  Answer yes or no on your whiteboard for the following properties;  1. malleability:  2. brittleness:  3. conductivity:  4. ductility : Assessment Time

  Magnetism – can be attracted by a magnet  Melting point – solid turns to liquid or liquid turns to solid  Boiling point – Liquid turns to gas or gas turns to liquid  Density – The amount of mass per volume of an object (g/cm 3 ) More Size-independent properties

  Use the magnet at your desk to test which of the items are magnetic  Write the magnetic items on the dry erase board and hold them up when you are done  Lead fishing weight   Copper wire   Aluminum can tab   Steel Bolt   Steel paper clip   Steel is a ferrous metal (contains iron – Fe)  Iron is magnetic! Assessment Time

  Changes in the appearance of a substance, but NOT what it is made of, is a physical change  Changes in size or shape  Changes of state  Ice melts to water  Water boils to vapor  It is still water Physical Changes

  Condensation  Gaseous H 2 O molecules cooling on a cold glass of ice water and forming water droplets on the outside  Sublimation  A gas going directly to a solid  Sublimation of Dry Ice (Solid CO 2 ) Sublimation of Dry Ice (Solid CO 2 )  Another Sublimation video Another Sublimation video  Cool sublimation trick Cool sublimation trick  Deposition  A solid turning directly into a gas More Physical Changes

  Mixture – formed when 2 or more substances come together, but do NOT combine chemically to make a new substance  Can be a combination of solids, liquids and gases  Soil is a mixture of sand, clay, silt, decaying plant and animal matter, air and water.  Salads are a mixture of vegetables, fruits, and dressing More Physical Changes

  The mixture is the same throughout  Salt and water mix together to make a saltwater  The salt seems to disappear  The salt and water molecules are spread evenly throughout  Salt dissolves in the water making a solution  The substance that dissolves is called a solute  The substance in which the solute dissolves is the solvent Homogeneous Mixture

  Write the words and answers on the white boards  In a salt water solution, identify the;  Solvent:  Solute:  Solvent: water  Solute: salt Assessment Time

  A measure of how much solute will dissolve in a certain amount of solvent at a certain temperature  The amount of solute compared to the amount of solvent is called concentration  A large amount of solute in a small amount of solvent would have a high concentration – unsaturated solution  A small amount of solute in a large amount of solvent would have a low concentration – saturated solution Solubility

  A mixture where the substances do not mix evenly  Suspension – the particles of one substance are temporarily mixed in another substance  Muddy water – the soil particles will eventually settle  Oil and vinegar salad dressing  Colloid – the particles are not dissolved, yet they do not settle out  In between a solution and a suspension  Milk  Gelatin  Mayonnaise  Fog – tiny water droplets in air Heterogeneous Mixture