Matter & Its Properties Objectives Distinguish between physical and chemical properties Classify changes as physical or chemical Explain gas, liquid, and solid states in terms of particles Mixture vs Pure Substance

Vocabulary Atom Change of state Chemical change Chemical property Chemical reaction Compound Element Extensive property gas Intensive property Liquid Mass Matter Mixture Physical change Physical property Product Pure substance Reactant Solid

Building Blocks Atom- the smallest unit of an element that keeps the properties of that element Element- pure substance composed of only one type of atom Compound- substance that is made from the atoms of two or more elements that are chemically bonded; changes the properties of all atoms

Properties Extensive Properties – depend on the amount of substance present –Volume –Mass –Energy present Intensive Properties – do NOT depend on the amount of substance present –Melting point –Boiling point –Density –Conductivity

Physical Properties/Changes Characteristic that can be observed without changing the identity of the substance Describe the substance  Melting point  Boiling point  Density Physical change – does not change the identity of the substance Change of state – changing from one phase to another

Solids, Liquids, and Gases Solids – have both definite volume and shape Liquids – have definite volume but not shape Gases – have neither definite volume or shape Particles have increasing velocity from solids to liquids to gases

Chemical Properties/Changes Changes the identity of the substance Chemical change – one or more substances are changed into new substances (chemical reaction) REACTANTS – what goes in PRODUCTS – what comes out  Combustion  Decomposition (break-down)

ENERGY Energy is ALWAYS involved heat light sound May cause physical or chemical changes

Mixtures A blend of two or more kinds of matter each retaining their own identity and properties Homogeneous – distributed evenly Heterogeneous – distributed unevenly MAY BE SEPARATED

Pure Substances Every sample has the same characteristic properties Every sample has the same composition

Classifying Matter MATTER Can it be separated? MIXTURE Homogeneous Mixture Heterogeneous Mixture PURE SUBSTANCE CompoundElement

Elements & The Periodic Table Periods – horizontal rows Groups – vertical columns Group 1A – alkalai metals Group 2A – alkalai earth metals Group 3A-12A – transition metals Group 16A – chalcogens Group 17A – halogens Group 18A – noble gases

Metals Conduct heat and electricity Malleable Ductile Luster (shiny)

Non-metals Poor conductors of heat Poor conductors of electricity Many are gases at room temp 5 solid non-metals –Phosphorous –Sulfur –Carbon –Selenium –iodine

Metalloids Have some characteristics of both metals and non-metals

Noble Gases Least reactive of all elements All gases at room temp