science chemistry test review

Chemistry test review ( summary) DEFINE MIXTURE : a substance made by mixing other substances together. PURE SUBSTANCE: Pure substance are made of only one type of atom or molecule, and the purity of a substance is the measure of the extent to which a given substance is pure. The physical properties of a pure substance include well-defined melting and boiling points. Ice melts : physical change Wood burns: chemical change A glass breaks: physical change A snowflake forms: physical change DEFINE SOLUTION : the process by which a gas, liquid, or solid is dispersed homogeneously in a gas, liquid, or solid without chemical change. MECHANICAL MIXTURE : a mixture whose components can be separated by mechanical means mixture is a substance consisting of two or more substances mixed together (not in fixed proportions and not with chemical bonding) Pure sugar : solution Salt dissolve in water : mechanical mixture Iron filings and sugar : mechanical mixture Marble and stones: mechanical mixture PHYSICAL PROPERTY : a characteristic of matter that can be observed with senses or measured CHEMICAL PROPERTY : a substances ability to change into a whole new substance CHMEICAL CHANGE : any changes in matter that creates a new substance "messing with the formula" PHYSICAL CHANGE : A change in size, shape, or state without forming a new substance texture : physical property Odour : chemical property Reaction with acid : chemical property Clarity : chemical property QUALITATIVE OBSERVATION : a non-numerical observation that describes the qualities of objects or events QUANTILITATIVE OBSERVATION : a numerical observation based on measurements or counting 6 B) Qualitative observation Quantilitative observation Qualitative observation Quantilitative observation Characteristic physical property : a property that is unique to a substance and that can be used to identify 7 B ) Melting point : Characteristic physical property Boling point : Characteristic physical property Density : Characteristic physical property Lustre : is not Characteristic physical property Element : a pure substance that cannot be broken down into simpler substance either physically or chemically Compound : a pure substance made up of two or more element that are chemically joined Q10 A ) Moth balls sublimate into air PHYSICAL CHANGE B ) iron rust on a car PHYSICAL CHANGE C ) wood is chopped into a little pieces PHYSICAL CHANGE D ) glasses is shattered with a hammer PHYSICAL CHANGE -a substance disappears. -a solid is formed. -a colour change occurs. -a new odour is produced. -a change of form (for example, burning paper).