Matter & Change Notes

Terms to Know A.Chemistry- The study of matter and the changes matter undergoes.

Terms to Know B. Mass- a measure of the amount of matter. C. Matter –anything that takes up space and has mass.

Four Phases of Matter SolidLiquidGasPlasma Properties Hard to compress Low energy Takes shape of container Volume is constant Easy to compress Takes volume of container Ionized (charged) gas Very high energy Drawing

Phases of Matter Simulation

Terms to Know D. Atom– smallest particle of an element that retains the chemical properties of the element E. Element- a pure substance made of only one kind of atom -from the Periodic table

Terms to Know F. Compound- composed of 2 or more elements in a fixed ratio –properties differ from those of individual elements EX: table salt (NaCl)

Learning Check: Classify each of the following as an element, compound, or atom: __________ ___________ _________

Properties of Matter A. Physical Properties of Matter - characteristics which allow us to recognize and distinguish it from another substance –Examples of physical properties are color, odor, density, melting and boiling points and its physical state (solid, liquid, gas) Purple, liquid, boils at 87 degrees.

A. Properties of Matter Intensive property – does NOT depend on amount of substance present; is constant, examples are density, melting or freezing points, heat capacity, solubility Extensive property – depends on amount of matter present. Ex: mass, volume

Properties of Matter B. Chemical Properties – the manner in which a substance reacts with another substance Ex: hydrogen reacts with oxygen to form water

Learning Check: Classify the following as chemical (C) or physical (P) properties: ____ Boils at 72°C ____ Is inert (does not react) ____ Is a liquid at room temp. ____Combusts in presence of O 2 P C P C

Learning Check Classify the following as intensive (I) or extensive (E) physical properties: ____ Melting point ____ Volume ____ Mass ____ Density I E E I

Changes of Matter A. Physical Changes of matter– do not involve the creation of a new substance. Ex: grinding, crushing, dissolving, change in phase.

III. Changes of Matter Know these 6 phase changes: Liquid Solid Gas Evaporation Condensation Deposition Sublimation Melting Freezing

Any change in state is a physical change…

A physical change is usually REVERSIBLE!!!

B. Chemical Changes of Matter Chemical Change - Involves changing one substance into a NEW SUBSTANCE: cannot get the original substance back: burning, fermentation, cooking a steak, etc.

Changes in Matter A chemical change is a chemical reaction. Mg + 2 HCl  MgCl 2 + H 2 Reactants products

Changes in Matter Signs of a chemical reaction: -Gas produced (bubbles) - Unexpected color change -Unexpected odor - Precipitate (solid) formed -Light given off - Heat given off or absorbed

Learning Check Are the following examples physical or chemical changes? ____1. rusting iron ____ 2. sugar dissolving in tea ____ 3. burning a log ____ 4. sweat evaporating ____ 5. grinding spices ____ 6. digesting food ____ 7. composting trash into soil ____ 8. dry ice subliming C P C P P C C P