Topic: Describing Matter Do Now: Get book and turn to Lesson 1

Properties – used to characterize matter Physical –how they look Chemical – how they react with others

Physical Properties

Describe the appearance and form of matter Words: color, texture, luster, odor, solid, liquid, gasMeasurements: a number and a unit

Chemical Properties

Describe how matter behaves in presence of other matter Describe how matter changes into another kind of matter –Flammable –Corrosive –Ability to neutralize acids or bases

Physical or Chemical? Reddish brown Forms new substances with HNO 3 MP = 1085  C Density = 8.92 g/cm 3 Reacts to form green copper carbonate Shiny Malleable BP = 2570  C - physical - chemical

Matter goes through changes

Changes Physical – identity remains the same Chemical – identity of matter changes

Physical Change

identityThe form or appearance of sample may change but identity remains same –Cutting, crushing, grinding,tearing –Phase changes –Dissolving

Dissolving is physical change Think of sugar in water still have sugar – you just spread it out with water molecules in between C 6 H 12 O 6 (s)  C 6 H 12 O 6 (aq) Aq = dissolved in water

Phase changes are physical changes No new substance is created (chemical formula stays the same) Ex: ice melting: H 2 O(s)  H 2 O(l) water boiling: H 2 O (l)  H 2 O(g)

Chemical Change chemical change - identity of matter is changed new substance with unique properties is formed Example - burning The chemical formula changes Ex: 2H 2 O(l)  2H 2 (g) + O 2 (g)

Evidence of Chemical a Chemical Change Bubbles (formation of a gas) Color change Heat Light Formation of a precipitate (new substance)