ackground Info. Chemistry - The study of matter & its changes Matter - Anything that has mass and takes up spa Examples of matter Examples of non-matter What kinds of changes can matter undergo?
Jan 19, 2016
ackground Info.
Chemistry - The study of matter & its changes
Matter -Anything that has mass and takes up space
Examples of matterExamples of non-matter
What kinds of changes can matter undergo?
Chemical Elements & Their Symbols
Where would you find a listing of all the elements?
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
Must learn some of the elements names / symbols:
(see handout)
Elements with symbols resembling their name:
Aluminum = AlCalcium = Ca
Zinc = ZnNitrogen = N
These are easier to memorize
Elements with symbols derived from foreign names: MUCH harder to memorize!
Element Name Older Foreign Name SymbolDo not need to know this!
Antimony Stibium Sb
Tungsten Wolfram W
Lead Plumbum Pb
Copper Cuprum Cu
ALL elements & their symbolsthat 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 todaylisted on periodic table
some are common, some are rare
can be solids, liquids or gases at room temperaturesome 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 monoxideCO
Nearly all advances in science have BOTH good & bad aspects
Examples: pesticides
DNA libraries
stem cell research
(Francis Bacon)
Points out the “Goods” of science
(Rachel Carson)
Points out the “Bads” of science
How do we know if we should usea particular scientific invention?
Weigh the risks and the benefits
any hazard,loss, injury
positive effects,promotes well-being
(DQ)
DQ = Benefits Risks
If benefits & risk DQ is
If benefits & risk DQ is
HIGH
LOW
would use
would NOT use
If benefits & risks are = DQ difficult to determine
Let’s do a couple together:
Depends on the point of view for individualfor whole society
Pasteurized milkThalidomide (morning sickness drug 1950’s)Aspartame (artificial sweetener)Nuclear powerOlean (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
Make the productperform
UnreactiveDOES NOT help
performance
Web Quiz
Antioxidants -Used in consumer products
to keep fats / oils frombecoming rancid
Smell & taste bad
against oxygen
Fat / oil + O2 spoiled foul smelling &
bad tasting chemicals
Antioxidants react with O2 before it can react with the fat or oil
Keeps product fresh longer!
2 Types of Antioxidants:
Natural - Vitamin CVitamin EVitamin A
Synthetic -Made in a laboratory
BHA (butylated hydroxyanisole)
BHT (butylated hydroxytoluene)
1. Find a product that contains BHA or BHT
2. Give product name
3. List first 5 ingredients
4. Does it contain BHA or BHT?
Due: __________________
Mass vs. Weight
Mass -A measure of the amount of mattersomething contains
Weight -A measure of the force of gravity on an object
Mass is the SAME EVERYWHERE
Weight DEPENDS ON LOCATION
prefer mass for this reason
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
Length =
Mass =
Volume =
meter
gram
liter
Metric Prefixes
BaseUnit
meter,gram,liter
Prefix
Abbreviation
Relation to base unit
kilo
k
1000
deci
d
1/10
centi
c
1/100
milli
m
1/1000
Larger thanbase unit
Smaller thanbase unit
Estimating Metric Measurements
Length1 m 1 yard
1 cm width of pinky1 mm width of dime
Mass1 g paper clip
1 kg 2 lbs.
Volume1 L 1 quart4 L 1 gallon
1 mL 10 drops
Let’s try some! (anyone want a calculator?)
15 gal gas tank ~ 60 L
Dr. Lotter 140 lb. ~ 70 kg
Textbook ? kg ~ 1 kg
Pen ? g ~ 10 g
Your height ~1-2 m
Length of textbook ? cm ~ 25 cm
Width of a nickel ? mm ~ 3 mm
oF oC
Boiling pt. of water
Freezing pt. of water
212 o
32 o
100 o
0 o
Which is ALWAYS smaller? Celsius!(keep this in mind)
Converting Temperatures
1. Add 40
2. Multiply or Divide by 1.8
3. 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 !
110 1.8 = 61
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- 40212 Answer = 212 oF
States of MatterSolid
Liquid
Gas
(Plasma)
Let’s learn more about these states through experiment
Solid Liquid Gas
Shape
Volume
Position ofMolecules
Compressibility
Definite
Definite Definite
IndefiniteIndefinite
Indefinite
Close Close Far Apart
NO NO Yes
Solid Liquid Gasmelting evaporation
condensationfreezing
sublimation
ADD Heat
REMOVE Heat
Physical Property -Can be observed with your sensesNo reaction with another substance
Chemical Property -Must have a reaction in order to seecolor, odor, hardness, melting point
flammable, oxidizes
Physical Change -happens with NO change in thechemistry of the substance
Chemical Change -Substance changes into a new substance
could reverse change
CANNOT reverse change withoutdoing a chemical reaction
Pure Substances -Always have the same composition
1. Element – made up of only 1 type of atom
Al, C, H, O2, U, Fe, Au
H2O, CO, CO2, NaCl
2. Compound – 2 or more types of atoms in a definite proportion
Mixtures -have a variable proportioncan be physically separated
salt + water
iron + sand
oil + water
sugar + sand
sand + water
2 Types of Mixtures:
1. Homogeneous -The same throughout
2. Heterogeneous -Different in spots
Kool-Aid, chocolate ice cream
sand + water, chocolate chip ice cream
Matter
SubstancesFixed composition
MixturesVariable composition
ElementOne type of atom
Compound2 types of atoms
HomogeneousSame throughout
HeterogeneousDifferent in spots