Download Atoms

Alchemy Unit
Investigation III:
A Particulate World
Lesson 1: Pudding and Clouds
Lesson 2: Building Atoms
Lesson 3: Subatomic Heavyweights
Lesson 4: Life on the Edge
Lesson 5: Shell Game
Lesson 6: Go Figure
Lesson 7: Technicolor Atoms
Alchemy Unit – Investigation III
Lesson 1:
Pudding and Clouds
ChemCatalyst
In the 5th century BCE a Greek
philosopher named Leucippus and his
student, Democritis, stated, “All matter is
made up of particles that can’t be divided
called atoms.”
• What do you think atoms are?
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
Lesson Essential Question
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
Periodic Table Groups
Group 1- Alkali Metals- these are
very reactive. Have even been
know to explode when water
touches them.
Sodium
Carbonate
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
Periodic Table Groups
Group 2- Alkaline Earth Metals
They are not nearly as reactive as
Group 1 but will form bonds easily.
Radium can be found in glowin–the-dark paint
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
Periodic Table Groups
Group 6- Noble Gases
This group will not form bonds with
other atoms.
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Unit 1 • Investigation III
Lesson Essential Question
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Unit 1 • Investigation III
You will be able to:
• Describe some models of an atom and
explain how they differ.
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
Notes
• Atoms are extremely small particles,
which cannot be seen, even with
microscopes.
• All matter is made up of atoms.
• Scientists have created models to
describe atoms. Models are similar to
theories, but often include a picture or
physical representation.
(cont.)
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
(cont.)
• Scientific evidence is a collection of
observations that many people have
made. Everyone agrees on the same
collection of observations.
• When a model is supported by
scientific evidence it is often
accepted by the scientific community.
• As new evidence is gathered, models
are refined and changed.
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
Parts of the
Atom
• A proton is a positively charged
particle that exists in the nucleus.
• A neutron is a neutral particle with no
charge on it that exists in the nucleus
• The electron is a negatively charged
particle that exists in an electron cloud
around the nucleus.
(cont.)
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
The Nucleus
• An atom is mostly empty space.
• There is the nucleus, which is located in
the very center of the atom.
• The nucleus is very small. .
• The nucleus is also very dense and
consists of two types of particles—
neutrons and protons.
(cont.)
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Unit 1 • Investigation III
Electron Cloud
A cloud around the nucleus where
the electrons can be found.
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Unit 1 • Investigation III
Notes (cont.)
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Unit 1 • Investigation III
Activity
Purpose: This lesson will introduce you
to various models for the atom that have
appeared over the past two hundred
years. The descriptions of five models of
the atom are on a separate handout.
(cont.)
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Unit 1 • Investigation III
Theories of the Atom
The History of the Atom
John Daltons Theory
Matter is made of atoms
Atoms can not be divided
into smaller pieces
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Unit 1 • Investigation III
Different elements are made
of different kinds of atoms
All atoms of an element are
exactly alike
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Unit 1 • Investigation III
John Dalton
John Dalton thought that
atoms looked like solid
spheres.
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Unit 1 • Investigation III
J.J. Thomson
Thought that the atom is a
sphere of positive charge
with negative charges spread
equally throughout.
Therefore, atoms have a
neutral charge.
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Unit 1 • Investigation III
Ernest Rutherford
Thought that the atom had a
nucleus (center) that was all
positive charge and electrons
(negative) that float around it.
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Unit 1 • Investigation III
Neil Bohr
Atoms have three
particles protons,
neutrons and
electrons. Electrons
exist in shells or
energy levels around
the nucleus.
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Unit 1 • Investigation III
Current Nuclear Model
Atoms has three
types of particles and
the electrons exist in
an electron cloud.
Protons (positive)
Neutrons (neutral)
Electrons (negative)
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
Making Sense
• From Pudding & Clouds: Examine the
date of the atomic evidence and then
put the five models in the correct order
of their introduction to the world of
science.
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
(cont.)
Five Models of the Atom
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Unit 1 • Investigation III
Check-Out
Here is a Bohr model of a carbon atom.
• List two things this model tells you
about atoms.
• List something this model does not tell
you about atoms.
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
History of the Atom Foldable
Create a tri-fold with the following information:
1. Each Scientists idea of the atom including
the persons name, description of what they
thought and a picture of their idea of the
atom.
2. Must be colorful and displayable!
3. Will be collected and graded!!
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
Wrap-Up
• All matter is made up of extremely
small particles called atoms. These
particles are too small to be seen even
with a microscope.
• Science is theoretical and dynamic.
Models and theories are continually
being revised, refined, or replaced with
new models and theories.
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
Alchemy Unit – Investigation III
Lesson 2:
Building Atoms
Copy these questions into your journal.
• Look at the following pictures and list
three similarities and three differences.
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Unit 1 • Investigation III
ChemCatalyst
A Bohr model of a helium atom and a
beryllium atom are given below.
Helium, He
Berylium, Be
(cont.)
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Unit 1 • Investigation III
The Big Question
• What does the periodic table tell us
about the structures of different
atoms?
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Unit 1 • Investigation III
You will be able to:
• Use the periodic table to identify the
properties of an elements atom.
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Unit 1 • Investigation III
Atomic
Number
• Atomic number is the number of protons in
the nucleus of an atom. This number is
above the chemical symbol.
• The number of electrons is always equal
to the number of protons in a neutral
atom.
• Ex. Lithium has 3 protons, therefore it
also has 3 electrons
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
Mass Number
• Mass number is the number of
protons plus the number of neutrons.
• You can find this by rounding the
number beneath the chemical symbol.
• Also referred to as atomic mass
because it is the mass of one atom of
the element.
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
Atomic Weight
1. Atomic Weight is the decimal number that is
found beneath the chemical symbol for an
element.
2. It is an average of all the different types of
atoms for that element.
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
Calculating the parts of the atom
Mass number (# of protons + neutrons)
minus
Atomic Number (# of protons)
____________________________
Number of neutrons
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Unit 1 • Investigation III
How to read and use an element key
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Unit 1 • Investigation III
Activity
Purpose: Label where the protons, neutrons
and electrons are in these atoms.
Beryllium Atom
Fluorine Atom
Carbon Atom
(cont.)
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
(cont.)
element
chemical
symbol
atomic
number
# of
protons
# of
electrons
# of
neutrons
beryllium
5
fluorine
10
6
18
lead
126
19
tin
35.45
39
70
tungsten
184
29
gold
atomic
weight
12
chlorine
potassium
mass
number
183.85
36
118
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
Making Sense
• If you know the atomic number of an
element, what other information can
you figure out about the atoms of that
element?
• If you know the atomic number of an
element, can you figure out how many
neutrons an atom of that element has?
Can you come up with a close guess?
Explain.
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
Bohrs Models
How to draw a Bohrs Model
First, find the number of protons, neutrons and
electrons
Draw a nucleus
Look at the period. This is the number of shells
the atom will have.
Ex. Elements in Period 2 have two shells
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Unit 1 • Investigation III
Continued
Look at the Group Number, this will tell you the
number of electrons in the last (outer) shell
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Unit 1 • Investigation III
Rules for Bohrs Models
There is a maximum amount of electrons that
can exist on each level.
Shell # 1 (next to the nucleus) can only have
up to two electrons
Shell # 2 can only have up to 8 electrons
Shell # 3 can only have up to 18 electrons
Shell # 4 can only have up to 32 electrons
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
Check-Out
1. Use your periodic table to identify the
following elements:
a) Atomic number 18
b) Has three electrons
c) Atomic mass of 16.0
2. How do you think a gold atom is
different from a copper atom?
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
Wrap-Up
• Each successive element has one
more proton than the element
preceding it.
• The atomic number is equal to the
number of protons.
(cont.)
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Unit 1 • Investigation III
(cont.)
• The number of electrons is equal to the
number of protons (as long as the
atom is neutral).
• The mass number is equal to the
number of protons plus the number of
neutrons (most of the mass is found in
the nucleus).
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
Alchemy Unit – Investigation III
Lesson 4:
Life on the Edge
ChemCatalyst
The three atoms below have similar
reactivity and chemical behavior.
• Where are these elements located on
the periodic table?
• What do you think might be responsible
for their similar properties?
(cont.)
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
(cont.)
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
The Big Question
• What accounts for the similar
chemistry of elements in the same
group?
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
You will be able to:
• Give the number of valence electrons
for an element.
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
Activity
Purpose: The various physical and
chemical properties of the elements can
be traced to the electrons. By studying
electrons further we may be able to
unlock the key to creating substances
similar to gold. This lesson will reveal the
arrangement of electrons within atoms.
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
(cont.)
Five Models of the Atom
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Unit 1 • Investigation III
Making Sense
• Explain how you can determine the
arrangement of an element’s electrons,
from the element’s position on the
periodic table.
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Unit 1 • Investigation III
Notes
• Bohr proposed that electrons could be
found in different shells around the
nucleus.
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Unit 1 • Investigation III
(cont.)
(cont.)
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
(cont.)
• The outermost shell of each drawing is
called the valence shell.
• The valence shell contains the
valence electrons.
• All other electrons are considered core
electrons.
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
Check-In
Provide the following information for
element number 34.
a) The element’s name and symbol.
b) The number of protons in the nucleus.
c) The total number of electrons for this
element.
d) The number of core electrons for this
element.
(cont.)
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Unit 1 • Investigation III
(cont.)
e) The number of valence electrons.
f) The group number for this element.
g) The names of other elements with
similar chemistry.
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
Wrap-Up
• Electrons occupy different shells
around the nucleus of an atom.
• Each electron shell can hold a specific
maximum number of electrons.
• The valence electrons are in the
outermost electron shell of an atom.
Electrons that are not valence
electrons are called core electrons.
(cont.)
© 2004 Key Curriculum Press.
Unit 1 • Investigation III
• Elements with the same number of
valence electrons have similar
chemistry and are in the same group.
© 2004 Key Curriculum Press.
Unit 1 • Investigation III