Atoms and Molecules · Essential Question How do scientists know what atoms look like? Today’s...
Transcript of Atoms and Molecules · Essential Question How do scientists know what atoms look like? Today’s...
Atoms and Molecules Monday, August 29, 2011
1. Open your journals to PAGE 27. Write “Black Box Inquiry” and 8/29/11 on the top line of the page.
2. Write the following on the next line of the page “Key Question – How do scientists know what molecules and atoms look like?”
3. Examine the sealed box. What do you think is inside? NO, you may NOT OPEN the box.
4. Discuss your ideas with your team.
5. Answer the following questions on page 27
1. What things do you think are in the box?
2. What influenced your thinking?
3. How did your group work out any differences of opinions of what was in your box?
4. How does this activity help you understand how scientists know what atoms and molecules look like?
Science Standard
S8P1. Students will examine the
scientific view of the nature of matter.
a. Distinguish between atoms
and molecules.
Today’s
Essential Question
How do scientists know what atoms look like?
Today’s Learning Goals
1. Identify and describe the three
subatomic particles, their charges, and
their location.
2. Construct model of four atoms.
3. Determine the total charge of an elemental atom is neutral.
Turn to page 28 of your
journal. At the top of the
page, write “Atom Notes”
and 8/29/11.
What is an atom?
An atom is the smallest particle into which
an element can be divided and still be the same substance.
What is an element?
An element is a pure substance that cannot be
separated into simpler substances by physical or chemical means.
Recapping…
An element is pure substance in which all
particles are the same. The particles that make
up an element are atoms.
For example, if you had a bowl of carbon,
every atom would be the same.
Atoms are:
a) too small to be seen by the human eye
b) contain a lot of empty space
c) have a nucleus made up of protons and neutrons
d) have electrons moving around the nucleus in a
“cloud”
All Matter is:
a) has mass
b) takes up space (volume)
c) is made up a smaller pieces called atoms
• ELECTRONS
• Smallest • Negative
charge
• PROTONS
• Second largest • Positive
charge
• NEUTRONS
• Largest • No charge
(neutral)
•Subatomic Particles Every atom is made up of…
An elemental atom has an equal number
of electrons (negative) and protons
(positive). The total charge of the atom is
zero or neutral.
For example, if an atom has 3 protons (+ + +) and
three electrons (- - -), the resulting charge would
be zero! Each positive charge (+) and each
negative charge (-) cancel each other out.
What holds the subatomic
particles together?
The electrons moving around the nucleus
in an atom are ATTRACTED to the protons.
However the protons in the nucleus
should REPEL or push each other away.
So... what holds the nucleus together?
Small particles called mesons hold the
protons and neutrons together in the
nucleus.
Laws of Electrical Charges
Like charges repel and unlike charges
attract
WE can use models to…
1) picture what we can not see 2) make predictions based on the model
If an atom is too small to be seen, how
can we study atoms?
In the Bohr model of the atom, electrons
are visualized as orbiting the nucleus like
planets orbiting Sun. There is a limit to the
number of electrons in any orbit because
electrons PUSH EACH OTHER AWAY (repel
each other).
The first electron level (orbit) allows __2__ electrons
before electrons start filling the next level.
The second electron level (orbit) allows _8___
electrons before electrons start filling the next level.
The third electron level (orbit) allows __8__
electrons before electrons start filling the next level.
The fourth electron level (orbit) allows _18__
electrons, and so forth...
Let’s construct a model of an atom with…
2 protons
2 neutrons
2 electrons
Nucleus
1st electron level
P
P
N
N
e-
e-
Let’s construct a model of an atom with…
4 protons
4 neutrons
4 electrons
P
P
N
N
e-
e-
P
P
N N e-
e-
Using the models at your table, construct
models for these atoms below:
1) 1 electron, 1 proton
2) 6 electrons, 6 protons, 6 neutrons
3) 8 electrons, 8 protons, 8 neutrons
4) 11 electrons, 11 protons, 12 neutrons
Raise your hands as a team when all
Four models are correctly built!
1. With a card in hand, each student mixes around
the room. Each finds a partner and quizzes him or
her by asking a question relating to their card.
2. Partner answers. Praise or coaching is given.
3. Switch roles. The other partner asks, then praises or
coaches.
4. Partners trade cards.
5. Partners split up and repeat steps 1 through 4.
6. Teacher calls “Freeze!”.
7. Students freeze, hide their cards, and think of their
match.
8. Students move to the center of the room,
find their match, and quickly move away
from the center of the room with their new partenr.