Unit 1 Matter: Properties and Change

What is matter? Matter – anything that takes up space and has mass. Matter – anything that takes up space and has mass. Mass – a measure of the amount of matter in an object Mass – a measure of the amount of matter in an object Weight is due to gravity; it changes from location to location; mass is always constant. Weight is due to gravity; it changes from location to location; mass is always constant.

States of Matter Definite Shape Definite Volume Temperature increase Compressible SolidYesYes Small expansion No LiquidNoYes Small/moderate expansion No Gas/VaporNoNo Large expansion Yes

What’s the difference between gas and vapor? Vapor – gas form of a substance that is normally a liquid at room temperature. Vapor – gas form of a substance that is normally a liquid at room temperature.

Types of Matter I. Pure Substance- one particular kind of matter; is uniform (all the same) and has a definite composition A. Elements – simplest kind of matter cannot be broken down any simpler cannot be broken down any simpler composed of only one kind of atom. composed of only one kind of atom. written shorthand w/ chemical symbols written shorthand w/ chemical symbols ex: carbon = C, iron = Fe, mercury = Hg

B. Compounds – made of two or more elements, chemically combined broken down only by chemical change broken down only by chemical change when broken down, pieces have different properties than original compound. when broken down, pieces have different properties than original compound.

II. Mixture- more than one kind of matter physically combined –has a variable composition –each part keeps its own properties –can be separated by physical means

A. Heterogeneous- mixture is not uniform in composition, (visibly different parts) ex: chocolate chip cookie, soil B. Homogeneous- same composition throughout; (all looks the same); Aka - solutions ex: Gatorade, air, salt water

Separating Mixtures Distillation – separates components of solution w/ different boiling points Distillation – separates components of solution w/ different boiling points Filtration – separates solid from a liquid using porous barrier Filtration – separates solid from a liquid using porous barrier Crystallization – forms pure solid particles from a saturated solution of dissolved particles Crystallization – forms pure solid particles from a saturated solution of dissolved particles Chromatography – separates components (mobile phase) across a piece of paper (stationary phase) Chromatography – separates components (mobile phase) across a piece of paper (stationary phase)

Properties of Matter I. Physical Properties – can be observed and measured without changing the composition. –color, odor, texture, hardness, density, melting and boiling pts. Physical change – change in appearance without changing the composition. - boil, freeze, dissolve, melt, condense, cut, bend, split, crack - boil, freeze, dissolve, melt, condense, cut, bend, split, crack

II. Chemical Properties – can only be observed by changing the composition of the material. Chemical change – a change where a new kind of matter is formed. Chemical change – a change where a new kind of matter is formed. - rust, rot, explode, burn, decompose, ferment - rust, rot, explode, burn, decompose, ferment

Indications of a Chemical Change Energy absorbed or released – temperature gets hotter/colder Energy absorbed or released – temperature gets hotter/colder Color change (sometimes) Color change (sometimes) Gas production – bubbling, fizzing, or odor change Gas production – bubbling, fizzing, or odor change Precipitate formed – solid that separates from solution and won’t re-dissolve Precipitate formed – solid that separates from solution and won’t re-dissolve

Law of Conservation of Mass matter can not be created or destroyed in chemical reactions – it is conserved matter can not be created or destroyed in chemical reactions – it is conserved Example: 2Na + Cl 2 2 NaCl reactants products 200 g + 15 g = 215 g 200 g + 15 g = 215 g mass of reactants = mass of products