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ackground Info. Chemistry -. The study of matter & its changes. Anything that has mass and takes up space. Matter -. Examples of matter Examples of non-matter. What kinds of changes can matter undergo?. Chemical Elements & Their Symbols.
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ackground Info. Chemistry - The study of matter & its changes Anything that has mass and takes up space Matter - Examples of matter Examples of non-matter What kinds of changes can matter undergo?
Element Symbols Rules: made up of 1 or 2 letters first letter is ALWAYS capitalized If a second letter; ALWAYS lowercase Ex: Sodium na Na NA NA na Which of the following represent elements? C CO Co CU Cd
Common Elements & Their Symbols Elements with symbols derived from foreign names: Common Elements & Their Symbols Elements with symbols derived from foreign names: Common Elements & Their Symbols Elements with symbols derived from foreign names: Must learn some of the elements names / symbols: (see handout) Elements with symbols resembling their name: Aluminum = Al Calcium = Ca Zinc = Zn Nitrogen = N These are easier to memorize
Elements with symbols derived from foreign names: MUCH harder to memorize! Element NameOlder Foreign Name Symbol Do not need to know this! Antimony Stibium Sb Tungsten Wolfram W Lead Plumbum Pb Copper Cuprum Cu
Memorize ALL elements & their symbols that are on the handout These are not all the known elements, but they are the ones we will encounter in our everyday lives You will have a QUIZ on them ________________!!!
Element - Substance where all atoms are the same ~ 110 elements known today listed on periodic table some are common, some are rare can be solids, liquids or gases at room temperature some are synthetic ALL matter is made up of elements BONUS POINTS: Bring in a sample of an element tomorrow
Compound - Substance made up of 2 or more elements (always in the same proportions) Can you name some compounds? Water H2O Carbon dioxide CO2 Table salt NaCl Carbon monoxide CO
The Goods & Bads of Science Nearly all advances in science have BOTH good & bad aspects Examples: pesticides DNA libraries stem cell research
Baconian Dream (Francis Bacon) Points out the “Goods” of science Carsonian Nightmare (Rachel Carson) Points out the “Bads” of science
How do we know if we should use a particular scientific invention? Risk-Benefit Analysis Weigh the risks and the benefits any hazard, loss, injury positive effects, promotes well-being
Desirability Quotient (DQ) DQ = Benefits Risks HIGH would use If benefits & risk DQ is LOW would NOT use If benefits & risk DQ is If benefits & risks are = DQ difficult to determine
Let’s do a couple together: Depends on the point of view for individual for whole society Pasteurized milk Thalidomide (morning sickness drug 1950’s) Aspartame (artificial sweetener) Nuclear power Olean (low-fat potato chips) Cloning
Project Pick ONE scientific / medical / technical invention Make a list of the “goods” & “bads” of this invention Prepare a display of this invention along with its benefits & risks (see examples from previous classes)
Reading Labels: FIRST ingredient listed - Present in the highest amount If sugar is first, product has more sugar than anything else Active vs. Inert Ingredients Unreactive DOES NOT help performance Make the product perform Web Quiz
against oxygen Used in consumer products to keep fats / oils from becoming rancid Antioxidants - Smell & taste bad Fat / oil + O2 spoiled foul smelling & bad tasting chemicals Antioxidants react with O2before it can react with the fat or oil Keeps product fresh longer!
2 Types of Antioxidants: Natural - Vitamin C Vitamin E Vitamin A Synthetic - Made in a laboratory BHA (butylated hydroxyanisole) BHT (butylated hydroxytoluene)
BONUS POINTS! • Find a product that contains BHA or BHT • Give product name • List first 5 ingredients • Does it contain BHA or BHT? Due: __________________
Mass vs. Weight A measure of the amount of matter something contains Mass - Weight - A measure of the force of gravity on an object
Mass is the SAME EVERYWHERE prefer mass for this reason Weight DEPENDS ON LOCATION
The Metric System Used all over the world except in the U.S. ALL scientists measure in the metric system Easier than English system because it is based on: 1
Base Units Length = Mass = Volume = meter gram liter
Metric Prefixes Smaller than base unit Larger than base unit kilo Base Unit meter, gram, liter deci centi milli Prefix Abbreviation Relation to base unit k d c m 1/10 1/100 1/1000 1000
Estimating Metric Measurements Length 1 m 1 yard 1 cm width of pinky 1 mm width of dime Mass 1 g paper clip 1 kg 2 lbs. Volume 1 L 1 quart 4 L 1 gallon 1 mL 10 drops
Let’s try some! (anyone want a calculator?) ~ 60 L 15 gal gas tank Dr. Lotter 140 lb. ~ 70 kg ~ 1 kg Textbook ? kg Pen ? g ~ 10 g Your height ~1-2 m ~ 25 cm Length of textbook ? cm ~ 3 mm Width of a nickel ? mm
Temperature oF oC Boiling pt. of water Freezing pt. of water 212 o 100 o 0 o 32 o Which is ALWAYS smaller? Celsius! (keep this in mind)
Converting Temperatures Lotter's Rule: • Add 40 • Multiply or Divide by 1.8 • Subtract 40 (must do all steps or it won’t work)
This classroom is about 70 oF. What is the temperature in oC? 70 + 40 110 Should we x or ? Celsius is always smaller Should ! 61 110 1.8 = • 61 • 40 • 21 Answer = 21 oC
Now you try alone: 100 oC = ________oF 100 + 40 140 Must x since oF is always larger 140 x 1.8 = 252 252 - 40 212 Answer = 212 oF
States of Matter Solid Liquid Gas (Plasma) Let’s learn more about these states through experiment
Definite Indefinite Indefinite Definite Definite Indefinite Close Close Far Apart NO NO Yes
Phase Changes sublimation melting evaporation Solid Liquid Gas condensation freezing ADD Heat REMOVE Heat
Physical vs. Chemical Change Physical Property - Can be observed with your senses No reaction with another substance color, odor, hardness, melting point Chemical Property - Must have a reaction in order to see flammable, oxidizes Physical Change - happens with NO change in the chemistry of the substance could reverse change Chemical Change - Substance changes into a new substance CANNOT reverse change without doing a chemical reaction
Classifying Matter Pure Substances - Always have the same composition • Element – made up of only 1 type of atom 2.Compound – 2 or more types of atoms in a definite proportion Al, C, H, O2, U, Fe, Au H2O, CO, CO2, NaCl
Mixtures - have a variable proportion can be physically separated salt + water iron + sand oil + water sugar + sand sand + water
2 Types of Mixtures: 1. Homogeneous - The same throughout Kool-Aid, chocolate ice cream 2. Heterogeneous - Different in spots sand + water, chocolate chip ice cream
Matter Substances Fixed composition Mixtures Variable composition Element One type of atom Compound 2 types of atoms Homogeneous Same throughout Heterogeneous Different in spots