1. What is matter? 2. What are the 3 states of matter? 3. Give one example each of an element, a compound, and a mixture. Actual SISS iron21.05% sawdust3.70% Values (write these down) sand: 56.76% salt: 18.49% Next lecture: bring some gum to chew (it must have sugar in it!)

is anything with mass and volume that takes up space and is made of ATOMS If I go over something in lecture REALLY fast, it’s probably not THAT important. If we spend time on something….then it IS important (AND covered on the test

Matter can be found as: ELEMENT  a pure substance made of ONE kind of atom. COMPOUND  substance made from 2 or more atoms that are stuck together (bonded). MIXTURE  combination of 2 or more substances

Matter Pure Substance (can write chemical formula) Compounds (2 or more bonded atoms) Elements (one type of atom) Mixture (more than 1 substance) Heterogeneous (not uniform) Homogeneous (uniform)

Pure substances Mixtures Whether they are homogenous or heterogeneous depends on their phase

Classify each example. If it is a substance, write ELEMENT or COMPOUND. If it is a mixture, write HETEROGENEOUS or HOMOGENEOUS in the mixture column. homogenous homogeneous heterogeneous homogenous element heterogeneous element compound homogenous

SOLIDLIQUIDGAS Keeps its shape.Does NOT keep its shape (takes shape of container). Can NOT be compressed (keeps same volume) Can NOT be compressed (keeps the same volume) Can be compressed to fit a smaller volume. Particles are relatively fixed.Particles are close but can flow past each other. Particles have a ton of energy and fly apart.

Session 4 – Matter and EnergyTNTP Chemistry Content Seminar  Many materials are naturally available in pure form. Mixtures can be separated physically, but it requires energy.  Evaporation – separates substances by their volatility. Allowing a volatile component of a mixture to evaporate off leaves the other component behind.

Session 4 – Matter and EnergyTNTP Chemistry Content Seminar  Chromatography –separates substances by the speed that they pass through a stationary phase  Centrifuge – separates solids by density through use of gravitational and inertial forces. More dense solids end up at the bottom of a centrifuge tube as the centrifuge spins.

Session 4 – Matter and EnergyTNTP Chemistry Content Seminar  Extraction – separates solutes by their differences in solubility in polar and non-polar solvents  Recrystallization –separates a solute by its solubility in a solvent. A super-saturated mixture is made and then the solubility is reduced (by cooling or adding another solvent) and the solute “crashes- out” of solution in crystal form. (ex. making rock candy).

Session 4 – Matter and EnergyTNTP Chemistry Content Seminar  Filtering – separates a solute by its phase. Filtering solids through filter paper and allowing the liquid filtrate to pass into a collection flask.  Decanting – separates a solute by its phase and density. Simply pour the liquid off of a solid-liquid mixture.

 Is this statement true? “Fog is air saturated with water, and as the air cools the water molecules get bigger and bigger until they become visible.”  No! Water molecules do not change in size. They can cluster and form liquid (fog!) or separate and form a vapor.  Distillation – uses difference in boiling points. Liquids are boiled and the vapors are condensed a different temperatures

Physical vs Chemical Changes: Evaporation vs. Electrolysis of H 2 O evaporation: H 2 O(l)  H 2 O(g) What bonds are disrupted? How do we know? Just ‘intermolecular forces’. The product is still water (vapor) which is NOT. flammable electrolysis: H 2 O(g)  H 2 (g) + O 2 (g) What bonds are disrupted? How do we know? Covalent bonds break, products are flammable BTW: We think of oxygen as a flammable gas, but oxygen is not a flammable gas-it does not burn…it supports the burning of other substances. By using the chemical properties of flammability and supporting burning, you can distinguish between the two gases hydrogen and oxygen.

Physical Changes:  cutting, melting, boiling, grinding, freezing, evaporating, condensing  The matter remains the same as the size, shape, or appearance changes.  Substance may require energy or release energy to undergo a phase change  H 2 0 (l)  H 2 0 (g)

Chemical Changes  fireworks exploding, matches burning, eggs rotting, bike rusting.  The matter changes to form a new substance that was not there before.  Four clues that a new substance has formed: 1. gas is produced 2. a new color is made 3. heat & light is given off 4. precipitate formed.

How Observant!