Transcript TODAY’S AGENDA Monday 1/5 Welcome Back!

TODAY’S AGENDA Monday 1/5
Welcome Back!
3)
FTF
What do you KNOW about Atoms?
1) How many parts are there in an Atom?
2) Can you name them?
Describe something unique about the parts of an atom.
4) What does an atom look like? (draw a picture)
TODAY IN SCIENCE CLASS
1. FTF
2. Bill Nye Atoms
3. Close Reading Activity
Homework:
SWBAT – Identify the parts and charges within an Atom.
Close Reading Activity
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Underline or circle items that you think are
important to know.
Make notes in the margins.
TODAY’S AGENDA Tuesday 1/6
FTF
Name the 3 parts of an atom.
2) What part has a positive charge? Negative? Neutral?
3) Where in an atom are the protons and neutrons found?
4) Where are the electrons found?
5) Can you draw an atom?
1)
TODAY IN SCIENCE CLASS
1.FTF
2.Atoms Textbook Reading & Notes
3.Atoms Hands-On Activity
4.Atoms Foldable for binder
Homework: Atomic Change and “On the Inside” worksheet
SWBAT – List the 3 parts of an atom and identify the charge of all 3.
INSIDE AN ATOM
Structure of an Atom
READ page 50 -51 in
the book. Stop at the
checkpoint.
Answer the checkpoint at
the top of your notes!
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An atom is the smallest part of
an element.
Scientists know atoms are
made up of even smaller
particles.
Structure of an Atom
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The nucleus is the tiny, central core of
an atom.
It contains protons and neutrons.
 Protons have a positive electric charge.
(+)
 Neutrons have no charge; they are
neutral.
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Electrons move in the space around
the outside of the nucleus.
Electrons are very energetic.
 They move in all directions
 Have a negative charge. (-)

•A proton is almost 2,000 times as massive as an
electron.
•Neutrons have about the same mass as protons.
Structure of an Atom
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In an atom, the number of protons
equals the number of electrons.
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The total positive charge and negative
charge balance making the atom neutral.
The number of neutrons may be the same,
but not always.
Count the number of electrons and
protons in the rings on the atoms to the
left.
What do you notice about the number
of protons and electrons in an atom?
Test Your Knowledge

How many protons would be in the nucleus of these
atoms? Write your answer in your notes.
??
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Did you say 6 and 18? Great Job!
??
Make Your Own Nucleus
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Use the green and orange circles to represent the
protons and neutrons of an atom.
The atomic # is equal to the number of protons in an
atoms nucleus.
Using the neutron and proton circles, on your desk make
a nucleus for
Carbon (atomic # is 6 and there are 6 neutrons)
 Calcium (atomic # is 20 and there are 21 neutrons)
 Aluminum (atomic # is 13 and there are 14 neutrons)
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Draw ONE of the above models in your notes!
Electrons in an Atom
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Electrons move around the
nucleus so fast it is impossible
to know where any electron is
at any particular time.
You can think of the space
around the nucleus as a
“cloud” of negatively
charged electrons.
TODAY’S AGENDA Wednesday/Thursday 1/7 & 1/8
FTF (homework out please!)
1)
Complete the Atoms Foldable and tape or staple into your
binder.
TODAY IN SCIENCE CLASS
1.FTF
2.Review homework
3.Finish Notes & Hands On Activity with Electrons
4.BrainPop Quiz
Homework: Bring earbuds/headphones tomorrow!
SWBAT – List the 3 parts of an atom and identify the charge of all 3.
Atom Mass and Volume
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Most of an atom’s mass comes
from its protons and neutrons.
Most of an atom’s volume is the
large space in which the
electrons move.
Valence Electrons
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An atom’s electrons are not all the
same distance from the nucleus.
The electrons that are farthest
away from the nucleus and are
involved in chemical reactions
valence electrons.
Only valence electrons are involved
in chemical bonding.
 8 is the highest possible number of
valence electrons.
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Make Your Own Atom
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Now try to create a model of a complete atom using
the electrons, neutrons and proton circles.
Nitrogen (atomic # is 7 and there are 7 neutrons)
 Sulfur (atomic # is 16 and there are 16 neutrons)
 Sodium (atomic # is 11 and there are 12 neutrons)
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Remember
There should be the same number of protons and electrons.
 The protons and neutrons go in the nucleus.
 The electrons circle in “clouds” or “shells” a far distances from the
nucleus.
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Draw ONE of the above models in your notes
How many valence electrons are in this
Carbon atom?
Valence Electrons
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A way to show the number of valence electrons that
an atom has is an electron dot diagram.
 It
includes the element symbol surrounded by dots.
 Each dot stands for one valence electron.
Let’s Practice
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Draw a valence electron diagram for the following
elements
 Helium
He (2 valence electrons)
 Oxygen O (6 valence electrons)
 Aluminum Al (3 valence electrons)
 Argon Ar (8 valence electrons)
 Nitrogen N (5 valence electrons)
Why Atoms Form Bonds
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A neutral atom never has more than 8 valence
electrons.
Most kinds of atoms have fewer.
2 things happen when atoms form bonds:
 The
number of valence electrons increases to a total of
8.
 All the valence electrons are given up.
Why Atoms Form Bonds
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When atoms end up 8 or 0 valence electrons, they
become less reactive. (Chemically Stable.)
Why Atoms Form Bonds
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A chemical bond forms between 2 atoms when
valence electrons move between them.
Electrons may be transferred from one atom to
another, or they may be shared between the atoms.
 Either
way, the atoms become bonded
 Reactions occur when atoms are bonded or bonds are
broken.
Models of Atoms
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Dalton Model: 1808
Dalton explained that each element is made of
small atoms.
Dalton imagined atoms as tiny, solid balls with
different elements have atoms of different mass.
Models of Atoms
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Thomson Model: 1897
Thomson suggested that an atom is a positively
charged sphere with electrons embedded in it.
His model was described as looking like a muffin
with berries scattered throughout.
Models of Atoms
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Nagaoka Model: 1904
Japanese physicist, Nagaoka, proposed a model of
an atom that had a large sphere in the center with
a positive charge.
His model showed the electrons revolving around the
sphere like the sun.
Models of Atoms
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Rutherford Model: 1911
Rutherford concluded that the atom is most empty
space.
Electrons orbit randomly around a small, positively
charged nucleus.
Models of Atoms
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Bohr Model: 1913
Bohr determined that electrons aren’t randomly
located around the nucleus.
This model showed electrons moving in specific
layers, or shells.
Bohr stated that atoms absorb or give off energy
when electrons move from one shell to another.
Bohr Model
Models of Atoms
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Chadwick Model: 1932
Chadwick discovered the neutron, a particle having
the same mass as the proton but with no electrical
charge.
The existence of the neutron explained why atoms
were heavier than the total mass of their protons
and neutrons.
Models of Atoms
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Modern Model: 1920’s-Present
The current model of an atom came from the work
of many scientists from the 1920’s-present.
It shows the electrons forming a negatively charged
cloud around the nucleus.
Quantum Model (currently accepted)