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2.1 - Properties of Matter. Extensive & Intensive Properties States of Matter Physical Properties & Changes. States of Matter Pre-Quiz. Which has the greater volume , the water in the test tube or the water on the counter?
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2.1 - Properties of Matter Extensive & Intensive Properties States of Matter Physical Properties & Changes
States of Matter Pre-Quiz • Which has the greater volume, the water in the test tube or the water on the counter? • Which has the greater volume, the sheet of aluminum foil or the ball? • Which has the greater mass, the sheet of aluminum foil or the ball? • Answers • Same Volume; Same Volume, Same Mass
I. States of Matter • Solids • Atoms are vibrating slowly and hold each other in place by intermolecular forces • Atoms are really close together (imagine them as “touching”) • Retains its shape because the atoms hold each together • Retains volume because atoms cannot get much closer or farther apart • Incompressible (Virtually) because atoms are already really close together
I. States of Matter • Liquids • Atoms are moving faster and are able to move around • Atoms are still really close together (imagine mosh pit) • Takes on the shape of the container because the atoms can move around each other and “flow” • Retains volume because atoms cannot get much closer together and they cannot escape each other • Incompressible (Virtually) because atoms are already as close as possible
I. States of Matter • Gases • Atoms are moving super fast and break free of one another • The atoms are widely separated (imagine a swarm of fruit fly’s) • Takes on the shape of the container because the atoms can move all over the place and “flow” • Takes on the volume of the container because atoms aren’t held together and can spread out in all directions • Easily compressed because atoms are far apart and can be easily squeezed closer together. • Vapor – used to describe a gas that is normally a solid or liquid (i.e. water vapor, “vaporize”)
Comprehension Check Fast Slow Medium Far Apart Touching Touching No Yes Yes No Yes No
II. Physical Properties & Changes • Physical Properties – anything that can be measured without a chemical reaction • Color, temperature, volume, shape, hardness, density, mass, weight, boiling & melting temperatures, etc. • Often used to identify materials • Physical Change – any change that does not affect the identity of the molecules that make up the material • Boiling, freezing, evaporation, change in shape, breaking, etc.