Matter and Change Matter is anything that has mass and takes up space Mass is the amount of material or “stuff” in an object

The building blocks of matter are atoms and molecules – the smallest unit of an element that maintains the properties of that element – a pure substance made of only one kind of atom; cannot be broken down any simpler Atom Elemen t

- a pure substance composed of atoms of different elements that are chemically bonded; broken down only by chemical means - a pure substance made of at least two atoms that are chemically bonded Compound Molecule

AlP4P4 H2OH2OCuCl 2 C 6 H 8 O 6 (ascorbic acid better known as vitamin C) Atom Element Compound Molecule YES NO YES NO YES NO YES NO YES NO YES

Properties of Matter words that describe matter (adjectives) Physical Property- a characteristic that can be observed or measured without changing the composition ex. colour, texture, M.P., B.P. Chemical Property- a property that can only be observed by changing the composition of the material ex. ability for charcoal (carbon) to burn in air

Physical Change

A. States of Matter There are four physical states of matter: Solid (s) matter that has a definite shape and volume because the molecules are close together and in relatively fixed positions Liquid (l) matter that has definite volume but an indefinite shape because the molecules are not so rigidly held and can move past one another (flows)

Gas (g) matter that has neither definite volume nor shape Plasma a gas-like substance that is variable in shape and volume ex: stars, fluorescent lights, CRTs

B. Kinetic Molecular Theory theory states that particles of matter are always in motion the kinetic energy (speed) of these particles increases as temperature increases

C. Four States of Matter Revisiting our four states of matter…. Solids very low KE: particles vibrate but can not move around fixed shape fixed volume

Liquids low KE: particles can move around but are still close together variable shape fixed volume

Gases high KE: particles can separate and move throughout the container variable shape variable volume

Plasma very high KE: particles collide with enough energy to break into charged particles (+ and -) variable in shape and volume

Mixtures is a physical blend of at least two substances (of variable composition) - mixture is not uniform in composition ex: chocolate chip cookie, soil, gravel -same composition throughout; called “solutions” ex: salt water, tea, Kool-aid - every part keeps it’s own properties Heterogeneous Mixture Homogeneous Mixture

Solutions Homogenous mixtures like all mixtures, each component keeps its own properties some solutions can be separated easily by physical means ( ex: jaw breakers and gum balls) and others by methods such as distillation (takes advantage of different boiling points) can occur between any state of matter – gas in gas; liquid in gas; gas in liquid; gas in solid; liquid in solid; solid in solid (alloys) etc.

Chemical Reactions a chemical reaction occurs when: one or more substances are changed into new substances Reactants- stuff the chemical reaction starts with Products- what the chemical reaction ends up making the ability to undergo chemical reaction is called a chemical property – Products have NEW PROPERTIES arrows from reactants to products

Indicators of a chemical reactions: energy absorbed or released (measurable by temperature changes) colour change gas production (bubbling, fizzing, or odor change) formation of a precipitate- a solid that separates from the solution and will not dissolve irreversibility- is not easily reversed

Law of Conservation of Mass law states that: mass cannot be created or destroyed by the means of ordinary (not nuclear) chemical reaction or physical change all the mass can be accounted for – ex: matter demonstration with sodium metal

Law of Definite Proportions law states that regardless of the amount, a compound always contains the same elements in the same proportions by mass Law of Multiple Proportions law states that when one element combines with another element to form more then one compound, the mass ratios of the elements in the compound are simple whole numbers of each other