Matter Pure Substances Mixtures Mechanical Mixtures Solutions Compounds Elements

Matter is something that has mass and occupies space (has volume). A pure substance is a kind of matter that cannot be separated into other kinds of matter by any physical process. A mixture is a composition of two or more pure substances (not chemically bonded) with each other and are capable of being separated. An element is a substance (homogenous) made up of one type of atom. A compound is a substance (homogenous) made up of one type of molecule or formula unit. A solution (homogenous mixture) is a mixture that displays one phase. A mechanical mixture (heterogeneous mixture) is a mixture that’s displays two or more phases.

Examples Elements: Compounds: Solutions: Mechanical Mixtures: Solutions and Mechanical Mixtures can be hard to distinguish. Liquid or gaseous solutions are transparent while mechanical mixtures are not (display the Tyndall effect). (air, pop, hydrogen in Pt, sea water, gasoline, dental amalgams (Hg in Ag), Brass (Cu, Zn), Bronze (Cu, Sn), solder (Sn, Pb)) (Suspensions: penicillin, Peptobismol, Milk of Magnesia, salad dressing, milk, paint colloids: whipped cream, shaving cream, )

Solutions are made up of a solvent which is the substance that dissolves one or more solutes. A solution retains properties from the solute and the solvent. Mechanical mixtures are heterogeneous which means that you can see the different particles in them (two or more phases). Two types of these mixtures seem homogenous but upon closer inspection are not. In a suspension the particles may be seen with the unaided eye or through a microscope. Over time gravity will cause the suspended particles to separate. If the suspended particles are small enough gravity will not cause the particles to separate. This type of mixture is a colloid. Mixtures are separated by physical means such as evaporation, distillation, freezing, filtration, flotation). Elements can only be broken down by nuclear reactions while compounds can only be broken down by chemical reactions) Read p Questions p

States of Matter There are three states of matter: solid, liquid and gas. Please sketch 20 water molecules in the ice form in a beaker. Next sketch 20 water molecules in the liquid form in a different beaker. Finally repeat this sketch for 20 molecules of water in the steam form. Matter Drawings Sketch 20 solid iron atoms. Sketch a solution of 20 water molecules and 10 sugar molecules. Sketch a mechanical mixture of 20 water molecules and 20 oil molecules before and after shaking.

Physical Properties A property is a quality or characteristic. - a diamond is hard - iron rusts The physical properties of a substance are those properties which can be determined without changing its composition or make-up. Physical properties include colour, odour, length, area, volume, mass, hardness, melting and boiling point, conductivity and density. Mercury is an odourless liquid with a silvery shine. It does not dissolve in water. It is an excellent conductor of electricity. It freezes at -39 o C and boils at 357 o C.

Chemical Properties The chemical properties of a substance are those properties which can be determined only when a substance undergoes a change in composition (chemical reaction). Gold is difficult to distinguish from fool’s gold. Fool’s gold reacts with nitric acid while gold does not. Carbon burns in air to produce carbon monoxide and carbon dioxide. Carbonic acid decomposes into water and carbon dioxide. Quantitative and Qualitative Properties A quantitative property is one that can be measured. Numbers will be used in expressing a quantitative property. Qualitative properties are those which cannot be expressed numerically. Examples include appearance and odour.

Physical Change A physical change is a change which alters one or more properties of the substance with no change in its composition or identity. -freezing, melting, boiling, condensing, evaporation, sublimation, breaking, tearing, bending, flattening What properties of the substance change in the following physical changes: melting, boiling, breaking, bending? Chemical Change A chemical change is a change in a substance which converts it into a different kind (or different kinds) of matter (each with a different composition and new properties).

Separating mixtures, conservation of mass, constant composition, evidence of chemical change