Transcript Intro to Chem

*
The
Atom
…
It would be a smart idea to take notes
today! Just saying…
By the end of these lessons students will be able to:
1)Correctly locate, identify and describe the three subatomic particles of the
atom.
2) Determine the number of neutrons, protons, electrons and element name when
given the atomic number and atomic mass.
3) Describe the differences and similarities of isotopes and their more standard
counterparts – and also explain how humans have used isotopes in dating things.
4)Accurately identify molecules, elements, atoms, and compounds.
5)Name the two general types of chemical bonds and explain how the electron
interaction works for both.
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Activity to lubricate
your brain (as
always)….
Step 1: Get into groups of at least 3 people
Step 2: Draw a picture of an atom (make sure each
part is correctly proportioned to each other part)
Step 3: Make sure your picture includes the
following: labeled parts (with an explanation of
what each part does), specify the number of each
part in your atom, and also name your element.
https://www.youtube.com/watch?v=oSCX78-8-q0
Diagram of a carbon monoxide molecule
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What things did
groups have in
common?
PARTS OF THE ATOM
Protons: Positively charged subatomic Particles found in the nucleus
Neutrons: Particles with no charge found in the Nucleus
Electrons: negatively charged subatomic Particles found in energy levels around
The atom (kind of…)
Nucleus: The center area of the atom containing just about all of the atomic mass,
which is found within the neutrons and protons that make up this location.
What would the general charge of an atom
be if you removed an electron? What if
you added an electron?
I.E.
Hydrogen has one proton and one electron,
so one + and one -….
What would the total charge be if you took away
that electron?
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WHY DO WE CARE ABOUT
THE CHARGE OF AN ATOM?
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Lets us try this again.
With bonding in mind.
Step 1: Fix or completely redraw your element to make it more
accurate (i.e. where the parts are, size of the parts compared to each
other, how many of each kind of particle)
Step 2: Also give your element a name, atomic number and atomic
weight.
Step 3: Try and bond your atom with another groups atom. Draw or
create bonds. Explain what is bonding and how.
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NOOOOOWWWW WHAT DID
PEOPLE HAVE IN COMMON?
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Bonding and electrons
are besties…
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Bonding!!! And
Electrons! and the two
can’t really be
separated…
https://www.youtube.com/watch?v=rcKilE9CdaA&index=
5&list=PL8dPuuaLjXtPHzzYuWy6fYEaX9mQQ8oGr
(more from Hank)
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How these atoms Bond!!!
Why do elements bond?
What elements do not bond?
Why do they not bond?
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THERE ARE TWO TYPES OF
BONDS:
COVALENT AND IONIC
BEFORE I EXPLAIN THE
DIFFERENCE YOU NEED TO
UNDERSTAND ‘ORBITALS’…
Covalent bonds SHARE electrons.
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What important substance do those
two elements become when they bond?
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In this scenario Sodium gives its extra electron to Chlorine. What
allows them to be bonded?
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Ionic Bonds: formed when one or more electrons are transferred from
one atom to another. These oppositely charged ions have a strong
attraction forming an ionic bond.
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What do you think would happen
when two polar molecules get near each other?
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A covalent bond is not the only bond undergone by a water molecule!
Water molecules ALSO have LOCO IMPORTANTE Hydrogen Bonds
between them!
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Tell me something good…..
Quick review with a little more detail…
Nucleus: The center area of the atom containing just about all of the atomic
mass, which is found within the neutrons and protons that make up this
location.
Protons: Positively charges subatomic particles found in the nucleus. The
number of these particles determines what element the atom is.
Nucleus: A non-charged subatomic particle also found in the nucleus,
necessary for the stability of the nucleus.
Electron: A negatively charged subatomic particle found in constant motion
around (but distant from) the nucleus. Equal in number to the protons in
standard atoms.
ISOTOPES!!!: atoms of the same element that
differ in the number of neutrons.
Is there a difference in charge with Isotopes?
Why or why not?
What would you call an Atom that had more or less
electrons than normally found in nature?
Also would that have a difference in charge?
22
Why is it called Carbon 14? What does the 14 refer to?
What do we call atoms with more neutrons than average?
What is attribute of the atom this difference affects?
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Carbon dating works for cells
Radioactive fallout from nuclear tests serves as measuring stick.
Roxanne Khamsi
How old are you? Carbon-14 can pinpoint the age of your individual cells.
© Getty
If wisdom comes with age, then brain cells are some of the wisest in the body: researchers have applied
carbon dating to DNA to confirm that cells in the brain live longer than most others.
This is a new application for the technique, which is traditionally used in archaeology and
palaeoanthropology to pinpoint the age of fossils.
Carbon dating looks at the ratio of radioactive carbon, which is naturally present at low levels in the
atmosphere and food, to normal carbon within an organism. While a creature lives, eats and breathes, its
ratio of radioactive to normal carbon will equal that of its environment. But when it dies, this ratio will fall,
as the carbon-14 decays.
Radioactive carbon decays slowly, such that a given amount of carbon-14 halves every 6,000 years. So
detecting the subtle change in the ratio of normal to naturally occurring radioactive carbon over just a few
years is incredibly hard.
But Jonas Frisén of the Karolinska Institute in Stockholm, Sweden, says it can be done if one takes
advantage of the signal left by nuclear testing, which spewed high levels of carbon-14 into the air during
the Cold War.
War babies
By the time a halt was called to aboveground nuclear testing in 1963, levels of carbon-14 in the
atmosphere had doubled beyond natural background levels, says Frisén. Since the halt, this has halved
every 11 years. By taking this into account, one can see detectable changes in levels of carbon-14 in
modern DNA, he says.
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How would you define ‘Element’?
WHAT IS AN ELEMENT?
Then what are these?
IMPORTANT DISTINCTIONS
Atom: Smallest unit of an element.
Element: A pure substance that consists entirely of one type of atom.
Compound: A substance formed by the chemical combination of two or
more elements in definite proportions.
Molecule: Two or more atoms joined together. A compound is a
molecule, but a molecule does not have to be a compound. i.e. O2 and
H2O
Do elements change very much
when they bond? Or are they just in
the same state but stuck together?
https://www.youtube.com/watch?v=NTFBXJ3Zd_4
https://www.youtube.com/watch?v=MsZhf2OnMKQ
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What are some properties of water
that are unique from other liquids? (Other
liquids being alcohols and oils, metals like
mercury…)
Why do these properties matter?
In what ways do they benefit life on earth?
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Now look at some of these properties
in real life…
Station 1: Salt crystal growing station/Water is the perfect Solvent
Station 2: Cohesion/Adhesion and Pennies
Each student will record this on a blank piece of paper. For each
station you will:
1) Write your name, your class period, the title of the station, the
date, and initial predictions
2) Record observations
3) Answer all prompts
It is your responsibility to hold onto these pieces of paper and bring
them to class. I will collect these at30
the end of the water property labs
for lab credit.
Possible Slide Show End
31
A little bit about electrons and electron
orbitals…
http://study.com/academy/lesson/covalent-bonding-and-electron-shells-definitionsrelationship-the-octet-rule.html
or https://www.youtube.com/watch?v=a8LF7JEb0IA
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You might, of course, say "Well, I know it isn't like this. The electrons
are arranged in a particular pattern - for example, in a diagram like this
one for sodium:"
That's fine - as long as you understand what the circles mean. The
circles are NOT orbits. The electrons are NOT moving around the
nucleus along the circles.
Instead, the circles represent energy levels. The electrons on the circle
closest to the nucleus have the lowest energy. The eight electrons on
the next circle have a higher energy, and the one on the outer circle has
the highest energy.
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*
Hank explaining basic
chemistry
https://www.youtube.com/watch?v=FSyAehMdpyI&index=1&list=PL8dP
uuaLjXtPHzzYuWy6fYEaX9mQQ8oGr