Physical Changes can be observed without changing the identity of the substance (often states of matter changes).

Transcription

1 Physical Changes can be observed without changing the identity of the substance (often states of matter changes).

2 Remember: States of matter changes are physical changes. The identify of the substance stays the same. Sublimation Melting Boiling Evaporating Solid Fixed Volume Fixed Shape Least Kinetic Energy Liquid Fixed Volume No fixed shape Moderate Kinetic Energy Gas No Fixed Volume No Fixed Shape Most Kinetic Energy Freezing Condensing Deposition

3 Physical and Chemical Properties of Matter Physical Properties/Changes Chemical Properties/Changes

4 Physical Properties Graphite the layered structure of the carbon atoms gives graphite its physical properties. The pattern of the atoms gives the substance its physical properties.

5 Physical Properties

6 Physical Changes can be observed without changing the identity of the substance( color, hardness, melting point & density) is only a change in any physical property of a substance matter can change from one state to another (liquid to a gas) Some physical changes would be boiling of a liquid melting of a solid dissolving a solid in a liquid grinding or crushing Condensation - when gas becomes a liquid

7 Physical Properties and Changes Recap The characteristics of a substance that can be observed without changing the identity of the substance are called physical properties. Examples: Color Shape Texture Volume Mass Density A physical change is any change in any physical property of a substance, not in the substance itself. Examples Breaking a piece of clay Stretching a rubber band Melting ice into liquid water Dry Ice sublimating into gas

8 Chemical Properties and Chemical Changes Chemical properties of a substance are defined by the chemical changes it undergoes. Chemical changes transform the substance into a new identify. Chemical change or chemical reaction is the transformation of one or more atoms or molecules into one or more different molecules.

9 Chemical Properties and Changes Chemical properties describe how substances can form new substances. A chemical property is any of a material s properties that becomes evident during a chemical reaction. Examples: Combustibility (ability to burn) Easily oxidized (ability to rust) Toxicity (level of harm to organisms) Reactivity with other chemicals Types of chemical bonds that will form Physical and Chemical Changes The change of one substance into another substance is called a chemical change. Examples: The burning of wood The rusting of iron Mixing baking soda and vinegar to produce carbon dioxide gas

10 Color Change Can be tricky to interpret Some color changes are just a mixture, not a chemical change Physical change mixing food coloring into water (mixture) Chemical change iron rusting due to oxygen (something new) Gas produced Has to be a new substance, not boiling! Temperature change Gets hot exothermic reaction Gets cold endothermic reaction Precipitate formed A solid is formed when reacting two or more fluids Odor change A new smell! Light or sound production Boom! Indicators of a Chemical Change

11 Physical vs. Chemical Examples: melting point flammable density magnetic tarnishes in air physical chemical physical physical chemical

12 Physical vs. Chemical Examples: -rusting iron -dissolving in water -burning a log -sublimation Chemical Physical Chemical Physical Chemical and Physical Change Practice Quiz #1 Practice Quiz #1; Practice Quiz #2 -grinding spices Physical

13 COMPLETE CHEMISTRY PACKET USING ONLINE TEXTBOOK Mr. Ganey s Webpage Science Booknotes (Textbook) Chemistry Textbooks Matter and Energy Textbook Chapter 2 Extension: Make vocabulary flash cards from Chapter 1 Study Guide (#1-18) and Chapter 2 Study Guide (#1-10)