Properties of Matter MSFWBAT: differentiate among element, compound, homo- and hetero-genous mixtures describe the arrangement and distances among particles in the solid, liquid, and gas state differentiate between chemically bonded and physically blended

Drill – 9/27 What is matter? What are the phases of matter?

Matter Has mass and Takes up space Can only be Separated Chemically, uniform and definite composition Can be separated Physically, not definite composition cannot be Separated into Simpler substance Contains two Or more elements Uniform throughout Not uniform throughout

WS:

Gas assumes the shape and volume of its container particles can move past one another compressible -lots of free space between particles flows easily particles can move past one another Liquid assumes the shape of the part of the container which it occupies particles can move/slide past one another not easily compressible little free space between particles flows easily particles can move/slide past one another Solid retains a fixed volume and shape rigid - particles locked into place not easily compressible little free space between particles does not flow easily rigid - particles cannot move/slide past one another

States of Matter Deposition

Drill 9.28 What factor(s) dictate what particular phase a substance exists in? 1. temperature (which is relative speed of particles of the substance) 2. pressure 3. distance between particles (can be related to pressure, but is not the same thing here) Any change to these variables can (theoretically) cause a phase change in any kind of matter

9.28 a. distinguish between physical and chemical properties b. contrast physical and chemical changes c. use law of cons of mass and energy to prove that mass remains constant during both physical and chemical changes

Physical & Chemical Properties! Physical properties: Do not change the chemical nature of matter Chemical properties: Do change the chemical nature of matter

Properties of Matter Physical Properties – Characteristics of a substance that can be observed or measured without changing the substance’s composition – Types of Physical Properties: colorsolubilitymass magnetism odorhardnessdensity melting point electrical conductivity boiling point

Properties of Matter Chemical Properties – describe chemical changes of a substance – Types of Chemical Properties rustrotdecompose fermentgrow

Classify the following as chemical or physical properties Freezing point Leaves rot A nail rusts Water turns to steam Something dissolves It explodes Reacts to form a gas Try some more on the next slide

It reacts to form carbon dioxide It smells bad It is shiny It is cut in half Tastes sweet A candle melts A balloon is blown up with air It burns Red color

Physical & Chemical Changes In a physical change, nothing new is created, the matter has just changed to another phase, separated or combined. In a chemical change, the substances are altered chemically and display different physical and chemical properties after the change.

Changes in Matter Physical Changes -changes which do not alter the identity of a substance Types of Physical Changes crush ortear changes in state (between solid/liquid/gas)

Changes in Matter Chemical Changes -changes (reactions) which alter the identity of a substance ** After a chemical change occurs a new substance is formed ** Types of Chemical Changes burningcooking chemical reaction with another substance

Physical Separations Predict how to separate each of the following heterogeneous mixtures: – Salt and pepper – Sand and iron filings – Mud (dirt from the water) – Fruit salad (the different types of fruit)

Focusing questions Indicate if the following are physical or chemical changes: 1.Wood burning 2.Plants growing 3.Cutting paper 4.Ice melting

“Separate This” WS

Techniques for Physical Separations Filtration Evaporation Centrifugation Chromatography Decantation Crystallization Distillation  Filtration Filtration  Evaporation Evaporation  Centrifugation Centrifugation  Chromatography Chromatography  Decantation Decantation  Crystallization Crystallization  Distillation Distillation

Filtration A mixture is poured into a funnel fitted with a piece of filter paper. Used for beer production and tap water (to remove solid impurities)

Evaporation A homogenous mixture is heated so that the water evaporates and just leaves the solid behind

Centrifugation Really fast spinning forces the solid or denser substance to the bottom of a sample

Chromatography A mixture is allowed to move along a fixed material. The components of the mixture move at different speeds (based on their attraction to the solvent and the material) and so they separate from each other.

Decantation Let the solid settle and then pour off the liquid, using something to block the solid

Crystallization The process of forming crystals. Used to separate solids from solution.

Distillation When a solution is heated, the liquid with a lower boiling point evaporates. The hot vapor that formed can be condensed back to liquid again on a cold surface. EVAPORATION + CONDENSATION

Chemical Separations Electrolysis Chemical Reactions Decomposition

Electrolysis Using electric current to force a chemical reaction with a separation occurring at the electrodes

Focusing question How would you separate a mixture of salt, sand, iron filings, ethanol and water into each of the components?

Law of Conservation of Matter and Energy Matter and energy cannot be created nor destroyed, only changed in form.

Energy Energy is the capacity to do work or to produce heat Forms of Energy – Potential – stored energy – Kinetic – energy of motion

Measuring Energy A calorie is the amount of heat needed to raise the temperature of 1 gram of water by 1 Celsius degree 1 cal = 1 gram x 1 C 0 The SI unit of energy is the joule (J) 1 cal = J