Matter and Change Chapter 2

Matter Substances Mixtures Element Compound Homogeneous Heterogeneous Can be physically separated Substances Mixtures Can be separated chemically Element Compound Homogeneous Heterogeneous

Properties of Matter Matter: Anything that has mass and takes up space Two ways to describe matter: Extensive: a property that depends on the amount of matter in a sample. (mass, volume) Intensive: property that depends on the type of matter in a sample, not the amount of matter. (hardness, melting point, color, boiling point)

States of Matter Solid: definite shape and volume Liquid: indefinite shape, flows, fixed volume Gas: indefinite shape and volume, compresses easily Vapor: gaseous state of a substance that’s liquid at room temp.

Identifying Substances Substance (or pure substance): matter that has a uniform and definite composition and can’t be separated without changing chemical composition. Every sample of a substance has identical intensive properties Substances can be either an element or a compound Element Compound Simplest form of matter that has a unique set of properties Substance that contains two or more elements chemically combined in a fixed proportion -can be broken down chemically

Mixtures Mixture: physical blend of two or more components Heterogeneous: composition is not uniform Homogeneous (aka solution): composition is uniform throughout

Hetergeneous or Homogeneous? Milk Chicken Noodle Soup Muddy Water Air Hot Chocolate Red Bull Apple Bronze

Complete the “Whatsa Matter” Worksheet with a partner! Partner Review!

Physical Property: quality or condition of a substance that can be observed or measured without changing the substance’s composition.(color, melting point, boiling point) Physical change: some properties of a material change, but the composition of the material does not change. Can be reversible or irreversible Words: boil, freeze, melt, condense, break, split, grind, crush, cut http://ishare.rediff.com/video/entertainment/diet-coke- mentos/676123 Physical Changes

Chemical Property: the ability of a specific substance to undergo a specific chemical change. (Ability to rust) Chemical Change (aka chemical reaction): A change that produces matter with a different composition than the original matter. The composition of matter always changes Words: burn, rot, rust, decompose, ferment, explode, corrode Chemical Change

Recognizing chemical changes Clues (although they can be tricky) Transfer of energy Change in color Production of gas Formation of a precipitate (solid that forms and settles out of a liquid) How can you know for sure it’s a physical or chemical change? Test the sample’s composition Recognizing chemical changes

Law of Conservation of Mass: in any physical or chemical change, mass is conserved. The mass of the products is always equal to the mass of the reactants. Conservation of Mass

Is it a chemical or physical change? Sugar dissolving in tea Chemical Change Physical Change

Is it a chemical or physical change? Logs burning Chemical Change Physical Change

Is it a chemical or physical change? Breaking water up by separating it into hydrogen and oxygen Chemical Change Physical Change

Is it a chemical or physical change? Metal rusting Chemical Change Physical Change http://tess.schoolwaxtv.com/learn-lab-files-physical-chemical-changes

Matter SWAT THAT! Physical Change Homogenous Pure Substance Chemical Change Matter Heterogeneous