Properties of Matter OBJECTIVES: Identify properties of matter as extensive or intensive. Define physical property, and list several common physical properties of substances. Differentiate among three states of matter. Describe a physical change.
MATTER Matter is anything that: a) has mass, and b) takes up space
MASS a measure of the amount of stuff (or material) the object contains (don t confuse this with weight, a measure of gravity) VOLUME a measure of the space occupied by the object
Which do you think would have the greater volume and mass? Why? 1 kg of feathers 1 kg of rock
Density is defined as mass per unit volume. It is a measure of how tightly packed and how heavy the molecules are in an object. Density is the amount of matter within a certain volume.
Proof that water and ice have different densities Ice floats in water 4 O C water is at its densest state Water molecules behave anomalously as it freezes
To find the density 1. Find the mass of the object 2. Find the volume of the object 3. Divide Density = Mass Volume 8
Units for density g/cm 3 or g/ml Formula: M = mass V= volume D = density M = D x V V = M / D D = M / V
To find density: 1) Find the mass of the object 2) Find the volume of the object 3) Divide : Density = Mass - Volume Ex. If the mass of an object is 35 grams and it takes up 7 cm 3 of space, calculate the density.
To find density: 1) Find the mass of the object 2) Find the volume of the object 3) Divide : Density = Mass - Volume Ex. If the mass of an object is 35 grams and it takes up 7 cm 3 of space, calculate the density. Set up your density problems like this: Given: Mass = 35 grams Unknown: Density (g/ cm 3 ) Volume = 7 cm 3 Formula: D = M / V Solution: D = 35g/7 cm 3 D = 5 g/cm 3
Properties are Words that describe matter (adjectives) Physical Properties- a property that can be observed and measured without changing the material s composition. Examples- color, hardness, m.p., b.p. Chemical Properties- a property that can only be observed by changing the composition of the material. Examples- ability to burn, acidity, reaction with oxygen, reaction with water, reaction with acid and bases, reaction with metal, decompose, ferment, etc.
Physical Properties Properties used to describe matter without changing its identity. It can be classified as: 1) Extensive depends on the amount of matter in the sample - Mass, weight, thickness, area, height, volume, calories, shape, length 2) Intensive depends on the type of matter, not the amount present -color, odor, taste, elasticity, porosity, hardness, density, freezing and boiling point, specific gravity
Chemical Properties chemical properties of matter is matter based on its ability to participate in chemical reactions and form new substances. Some chemical properties are: 1. Reaction with oxygen (combustion) 2. ph (reaction with Acids and Base) 3. Corrosion 4. Decomposition into simpler substance
COLOR A visual attribute of things that results from the light they emit, transmit or reflect
ODOR smell or the sensation that results when receptors in the nose are stimulated by particular chemicals in gaseous form
LUSTER The visual property of something that shines with reflected light OPACITY The phenomenon of not permitting the passage of electromagnetic radiation
MALLEABILITY The property of being physically malleable; the property of something that can be worked, hammered or shaped without breaking DUCTILITY The malleability of something that can be drawn into threads, wires or hammered into thin sheets
CONDUCTIVITY A material's capacity to conduct electricity, sound, heat
HARDNESS The property of being rigid and resistant to pressure; not easily scratched; measured on Mohs scale
BOILING POINT The temperature at which a liquid boils at sea level MELTING POINT The temperature below which a liquid turns into a solid
DENSITY amount of MASS mass per volume amount of matter WEIGHT The vertical force exerted by a mass as a result of gravity
VISCOSITY resistance of liquid to flow VOLUME The amount of 3-dimensional space occupied by an object LENGTH longest side of an object. A distance between 2 points
SOLUBILITY (solution) the quantity of a particular substance that can dissolve in a particular solvent (yielding a saturated solution) VOLATILITY The property of changing readily from a solid or liquid to a vapour
States of matter Solid- matter that can not flow (definite shape) and has definite volume. A. Incompressible, rigid and compact B. Do not flow C. Melt
Liquid- definite volume but takes the shape of its container (flows). A. Ability to flow and viscosity B. Diffusion C. Definite volume D. Surface tension E. Capillary action F. Vaporization or evaporation
SURFACE TENSION is a contractive tendency of the surface of a liquid that allows it to resist an external force CAPILLARY ACTION A phenomenon associated with surface tension and resulting in the elevation or depression of liquids in capillaries
Diffusion the process in which there is movement of a substance from an area of high concentration of that substance to an area of lower concentration
Gas- a substance without definite volume or shape and can flow. A. It has no definite shape and volume B. It diffuses easily. It flows C.It can be compressed. D.It exerts pressure.
States of Matter Solid Definite Volume? YES Definite Shape? YES Result of a Temperature Increase? Small Expans. Will it Compress? NO Liquid YES NO Small Expans. NO Gas NO NO Large Expans. YES
4 th state: Plasma - formed at high temperatures; ionized phase of matter as found in the sun
Three Main Phases
Freeze Melt Condense Evaporate Solid Liquid Gas
Copper Phases - Solid
Copper Phases - Liquid
Copper Phases Vapor (gas)
Physical vs. Chemical Change Physical change will change the visible appearance, without changing the composition of the material. Boil, melt, cut, bend, split, crack Is boiled water still water? Can be reversible, or irreversible Chemical change - a change where a new form of matter is formed. Rust, burn, decompose, ferment
Examples of Physical Change water evaporating or water changing to steam clothes drying in a dryer chopping wood - wood ground to sawdust erosion rock breaking mixing Kool-Aid
Examples of Chemical Changes fruit rotting, food spoiling rust decay of plants burning wood silver tarnishing car burning gas baking bread
Chemical Changes The ability of a substance to undergo a specific chemical change is called a chemical property. iron plus oxygen forms rust, so the ability to rust is a chemical property of iron During a chemical change (also called chemical reaction), the composition of matter always changes.
Chemical Reactions are When one or more substances are changed into new substances. Reactants- the stuff you start with Products- what you make The products will have NEW PROPERTIES different from the reactants you started with Arrow points from the reactants to the new products
Chemical Change Evidence 1. Precipitate forms (solid) 2. Gas evolves (bubbles) 3. Color change 4. Energy change» Exothermic = releases energy» Endothermic = absorbs energy 5. Odor produced (sometimes) 6. Irreversibility - not easily reversed But, there are examples of these that are not chemical boiling water bubbles, etc.
Chemical changes Rusting of nails Baking cake Fermentation of rice washing Tarnishing of a silver spoon Dissolving antacid in water Physical changes Setting of a jelly Melting butter Boiling water Sawing a board in half Breaking a glass
Conservation of Mass During any chemical reaction, the mass of the products is always equal to the mass of the reactants. All the mass can be accounted for: Burning of wood results in products that appear to have less mass as ashes; where is the rest? Law of conservation of mass
reactants = product - Page 55 43.43 g Original mass = 43.43 g Final mass
1. Is this a physical or chemical change? dirt added to a pond of water Physical Change
2. Is this a physical or chemical change? making whip cream Physical Change
3. Is this a physical or chemical change? baking soda fizzes with vinegar Chemical Change
4. Is this a physical or chemical change? sharpening a pencil Physical Change
5. Is this a physical or chemical change? a stick broken into small pieces Physical Change
6. Is this a physical or chemical change? sugar turns brown, then black with heat Chemical Change
7. Is this a physical or chemical change? using hot water to expand a metal cup Physical Change
8. Is this a physical or chemical change? freezing water Physical Change
9. Is this a physical or chemical change? cornstarch turns black with iodine Chemical Change
10. Is this a physical or chemical change? toasting a marshmallow Chemical Change