Block 3 & 4
Dalton’s Atomic Theory & Rounding
Warm-Up
• Pick up handouts & put away cell phones!
• Finish collecting the lab data. WEAR YOUR LAB
GOGGLES!
• If you’re done start working on your conclusion.
Warm-up
• Pick up handouts & put away cell phones!
• On a sheet of paper under the warm-up section of
your binder answer the following in complete
sentences!
• Title: Theory of the Atom
• The first idea of the atom was brought about in
400 BC. Write an entry to the Roman
Philosophers Committee on your theory of the
atom.
Instrumentation & Measurement
• The more divisions of
measurement the
more EXACT we can
be.
• The more decimals
(or significant figures)
the more exact a
measurement is
• When is it important
to have exact
measurements?
How can we increase precision?
• Increasing the numbers of significant digits!
• Significant digit- all numbers in a measurement plus
an extra for estimation.
6.60 mL
6.63 mL
Take Away
• Accuracy- how close a measured value is to an
accepted value
• Precision- how close a series of measurements are
to one another
Practice: The known mass of Cobalt is 58.93 g/mol
Both accurate & precise
• 58.9, 58.92, 59.0
• 50, 51, 45
Not accurate or precise
• 62, 62.1, 62.0
Precise but not Accurate
Learning Check
• On a quarter sheet of paper write your name &
period
• Title: Learning Check- METRIC
• Answer the following on your own
1. What instrument do we use to measure volume?
2. Write BOTH conversion factors for how many mm
in a cm
3. ______ Hg in 43.2 cg
ATOMIC THEORY FOLDABLE
• With the paper horizontal,
fold two flaps of equal size
inward
• Vertically fold paper into
thirds. Open back up.
• Cut along the horizontal folds
on the FRONT FLAPS ONLY
Roots of Atomic Theory
• Democritus
•
•
•
•
1st proposed idea matter was no infinitely divisible
Matter made of particles called atomos
Atoms cannot be created, destroyed, or further divided
Different atoms have different sizes and shapes
Aristotle
• Empty space cannot exist
• Matter is made of earth, fire, and water
Atomic Theory Postulates
• It took 2,000 years to disprove Aristotle’s idea of
nature.
• Postulate- a thing suggested or assumed as true,
existent, or fact as a basis for reasoning, discussion,
or belief
• Revise your warm-up idea or expand it based on
the previous philosopher’s concepts.
John Dalton
• Sept 6th 1766 – July 27th 1844
• First job age 10
• Became a teacher at 12
• Proficient in Latin by 14
• Meteorology, Color Blindness, & Hiking
• Atomic Theory from studying gasses in 1803
All matter consists of a large
number of tiny particles
• Matter
• Anything that has mass and takes up space
• Atom
• smallest particle of an element that retains the
properties of the element
Atoms of an element are unique,
indestructible, and indivisible
• Element- pure substance that
cannot be broken down into
simpler substances
• Each element has its own
characteristics
• Atoms cannot destroyed or
divided
• Smallest unit of matter
Atoms of a given element are
identical in size, mass, and chemical
properties
• Mass
• measure that reflects the amount of
matter
• Chemical property
• ability or inability of a substance to
combine with or change into one or
more new substances
Chemical rxn involve separating,
combining, or rearranging of atoms
• Atoms are neither created, destroyed, divided into
parts, or converted into atoms of another element
• Chemical reaction (rxn)
• Process by which the atoms of one or more substances
are rearranged to form different substances
• Indicated by change in temperature, color, odor, and
physical state
Block 4
• Phones away! I’m going to make sure there are 4 in
every box!
• Turn in your metric one step worksheet & work to
the black trays
• WARM-UP: On page 11 of your packet, complete
the chart on Dalton’s Postulates as best you can.
Try not to use your foldable!
Homework
• Learning Sapling Due
Thurs 11:00 pm
• Content Quiz Next
Block!
• Pg 11- Review Dalton’s
Postulates #1-5
Content
• Dalton’s Postulates
• Rounding Numbers
• Metric One-Step
Conversions
Language of Chemistry (LoC) List 1
x2
The “2” is a subscript
x2
The “2” is a superscript (l) liquid. written after a
chemical formula
2x
The “2” is a coefficient (g) gas. written after a chemical
formula
→ “yield”; shows a chemical
reaction took place
(s) solid. written after a
chemical formula
(aq) aqueous. written after the
formula for a chemical dissolved
in water.
Chemical formula A2B, element symbols and subscripts
Chemical equation 2A + B → A2B, chemical formulas, a yield sign,
and coefficients (usually)
Element Quiz Remediation
• On the back of your quiz write the elements you
got wrong 3 times each
• Name, Symbol, Name, Symbol, Name, Symbol
• IN A STRAIGHT LINE
• We always go by the spelling on the periodic table
TRADE & GRADE HMWK
• DO NOT grade your own paper.
• Write you name NEATLY on the right side of the
page
• IF I find a mistake or you “grade nicely” not only
will I regrade that person’s paper, but I’ll take the
same points off your paper!
ROUNDING NUMBERS!
Packet Pg 4
Classifying Matter
• Using your notes & the textbook, define the
three types of matter discussed in Dalton’s
atomic theory on PG 11 of your packet
• Element
• Compound
• Mixture
Element Vs. Compound
• Elements are PURE SUBSTANCES found on the
periodic table
• Compounds are two or more elements chemically
bonded together
Diatomic Molecules
• Two of the same element bonded together is called
a diatomic Element
• They are unstable being alone and must bond to
themselves
• Br I N Cl H O F
Mixtures
• Two or more different substances that are not
chemically combined and can be separated through
physical means
• Heterogeneous mixtures- does not have uniform
composition; can see different substances
• Homogeneous mixtures- uniform composition and a
single phase; also called a solution
Let’s Practice Pg 13
LAB ACTIVITY
• You will find samples at each lab station
• You must do each of the following for every
sample:
• Label by Table Number
• Write a short qualitative description
• Determine if it is a element, compound, or mixture
• Total of 12 Samples!
• There can be more than 1 think in each container
In your groups
• Look at the labels I’ve handed you and the
descriptions you made with a partner
• What table(s) would you place your description at?
• Have one person at your table go place your labels
next to the sample you believe it is
Homework
• Learning Sapling Due
Thurs 11:00 pm
• Content Quiz Next
Block!
• Pg 11- Review Dalton’s
Postulates #1-5
Content
• Dalton’s Postulates
• Rounding Numbers
• Metric One-Step
Conversions
Metric REVIEW
SHOWDOWN
• The Captain of your team is the person with the
next birthday.
• You will write your answer on the board and keep it
to yourself.
• Once everyone has had a chance to answer your
captain will say “showdown”
• Everyone should compare answers. Talk about any
differences and come to a conclusion.
• If you get the question correct you get a point.
Captians keep tabs on the points!
Write the conversion
fraction for how many
centigrams in a gram.
What is the conversion
factor for how many
millimeters are in a meter
Conversion Factor for
kiloliters in a liter
How many cg is 56.7 g
SHOW YOUR WORK
If the next town is 96 km
away how far do I have
to drive in meters?
Show all work
A fat cat masses 23,004
mg. how fat is the cat in
g?
How many sigfigs did the
mass of the fat cat have?
23,004 mg
What is the estimated
digit for a volume
reading of 56.89 mL?
What is the estimated
digit for a volume
reading of 56.89 mL?
Draw the instrument used to take this
reading. BE SURE to mark the proper
measurement lines!
If a flame burned for 450
milliseconds, how fast did it
burn in Dekaseconds?
Make sure you go to the base unit!
(TWO STEP CONVERSION!!)