Download Atoms defy what we thought we knew! 1902 Ernest

Use your jigsaw notes:
1.
Which atomic model showed the
probable locations of electrons?
2.
Which atomic model was the first to
show the nucleus of an atom?
3.
Which atomic model was first to show
energy levels?
Day 1 12-13
We have Atoms! – 1898
Marie Skłodowska Curie and Pierre Curie
• Investigated
radiation and its
_________
behaviors.
• The chemical
properties of
radioactive elements
change as radiation
_______
is emitted.
We have Atoms! – 1898
Marie Skłodowska Curie and Pierre Curie
• Isolated and
discovered the
polonium
elements _________
radium
and ________.
We have Atoms! – 1899
Ernest Rutherford
radiation to determine
• Analyzed ________
composition
its ___________.
Alpha particles  , are fairly
–______________,
positive charge.
heavy with a ________
Beta particles  , are
–_____________,
negative
very tiny with a ________
charge.
We have Atoms! – 1899
Ernest Rutherford
Beta particles  , are
–_____________,
negative
very tiny with a ________
charge.
Gamma rays g , have no
–____________,
neutral
mass with a _______
charge.
Radiation Penetration
Radiation Separation
• What does this separation pattern
indicate about charges and masses
of these types of radiation?
larger mass and ________
positive charge
–α: ______
–β: ________
smaller mass and _________
negative
charge
Radiation Separation
• What does this separation pattern
indicate about charges and masses
of these types of radiation?
smaller mass and _________
negative
–β: ________
charge
no mass and ___
no charge
–γ: ___
Atoms defy what we thought we
knew! - 1900
Max Planck realized that atoms
have their own rules
_________________.
Good-bye, Newtonian physics!
Hello, Quantum Physics!
Atoms defy what we thought we
knew! 1902
• Ernest Rutherford and
Frederick Soddy discovered
that radioactivity produces
elements
new __________
• Nuclear decay of uranium238
Atoms defy what we thought
we knew! 1902
• Nuclear decay of uranium238
Mass #
238U → 234 Th + 4He
2
92
90
Atomic #
uranium-238 → thorium-234 + α particle
Use your notes:
1. Which type of radiation is the
most dangerous (penetrating)?
2. Which type of radiation is made
up of high speed electrons?
Day 2 12-14
Read pages 105-109 and answer #s
9-15 on page 109
Atoms defy what we thought
we knew! 1902
• Nuclear decay of uranium238
Mass #
238U → 234 Th + 4He
2
92
90
Atomic #
uranium-238 → thorium-234 + α particle
Mass # = protons + neutrons
Atomic # = protons – periodic
table
Write the nuclear symbol for
Carbon with 6 neutrons
Write the nuclear symbol for
Carbon with 8 neutrons
Practice
For Neon with 9 neutrons:
19
Mass #? _____
# of protons? _____
10
10
atomic #? _____
Write the nuclear symbol:
Practice
If an atom has 7 protons + 9 neutrons:
16
Mass #? _____
element = ? _________
nitrogen
atomic #? ____
7
Write the nuclear symbol:
Practice
Uranium-239:
239
Mass #? _____
protons? ____
92
atomic #? ____
92
Write the nuclear symbol:
Practice
If an atom has 17 protons + 18 neutrons:
35
Mass #? _____
element = ? __________
chlorine
atomic #? ____
17
Write the nuclear symbol:
Assignment # 1 Unit 3
Atoms defy what we thought
we knew! 1909-1910
• Ernest Rutherford’s
–Experiment applet #1
–Experiment applet #2
• Ernest Rutherford’s
Atom’s appearance:
Hollow sphere
– ____________________
Dense center with positive charge
– ____________________________________
Electrons occupy empty space
– ________________________________
Atoms defy what we thought
we knew! 1912 - 1913
• Neils Bohr - modified Rutherford’s
atomic model.
specific
–Electrons are located in _______
energy ______.
levels
______
Used this model to explain
emission __________
spectra
_________
Atoms defy what we thought
we knew! 1912 - 1913
• Neils Bohr - modified Rutherford’s
atomic model.
–When an electron becomes excited
(gains energy) it can jump up to a
new energy level.
When it falls back down
to its ground state it
emits energy (light).
Atoms defy what we thought
we knew! 1913
• Frederick Soddy coined the term
isotope
_______
–Atoms of the same ________
element
weight
–Differ in _______
radioactivity
–Differ in ___________
–Examples
Carbon-12 and Carbon-13
• ________________________
Uranium-236 and Uranium-238
• _________________________
Atoms defy what we thought we
knew! 1913
• Henry Moseley
atomic ________
numbers to
–Assigned ______
each element
–Realized that
something in
nucleus of
the _______
an atom
determines …
Atoms defy what we thought we
knew! 1913
• Henry Moseley
–Realized that
something in
nucleus of
the _______
an atom
determines its
position on the
_______
_____.
Periodic Table
Atoms defy what we thought we
knew! 1919
• Ernest Rutherford discovered
protons
_______
positive charge and are
–Carry a _______
nucleus
found in the ______.
protons is the
–The number of _______
number
atom’s atomic
______ _______.
artificial
–Conducted the first _______
transmutation reaction, …
____________
Atoms defy what we thought we
knew! 1919
• Ernest Rutherford discovered
protons
_______
artificial
–Conducted the first _______
transmutation reaction, changing
____________
nitrogen-14 into the
the element __________
element ________
oxygen-17
14N
7
+
4He
2
→
17
O
8
+
1H
1
Atoms defy what we thought
we knew! 1926
quantum
• Neils Bohr’s ________model
of the
atom
–______
_____
Empty sphere
Nucleus is dense center with
–_______
positive _______
protons
______
Electrons found in specific
–________
energy levels
Atoms defy what we thought
we knew! 1926
quantum
• Neils Bohr’s ________model
of the
atom
Electrons found in specific
–________
energy levels
–Formula for the maximum
number of e- per level:
e
2
2n
Max # =
n = number of energy level
Atoms defy what we thought
we knew! 1932
• James Chadwick
neutrons
discovered _________
charge
–Have no _______
–Located in the atom’s
nucleus
_______
Atoms defy what we thought we
knew! 1938
• Lise Meitner was the first to
correctly describe a nuclear
fission
________ reaction in which a large
nucleus is split into two smaller
nuclei of approximately equal size.
235U + 1n → 236
92
0
92
236
1
141
92
n
3(
)
→
Ba
+
Kr
+
92
0
56
36
U
U
Today: Is matter continuous or
discontinuous?
• What are protons, neutrons, and
electrons made of?
quarks, bosons, muons, gluons, etc!
• What about string theory?
Is there a tiniest piece of energy
that everything is made of?
Today: Is matter continuous or
discontinuous?
Is there a tiniest piece of energy
that everything is made of?
• When you ask “What is the
smallest piece?”, be certain to
specify what you want!
–Cmpd. = group of bonded atoms
–Element = single atom
–Atom = ??
Parts of Atoms, Isotopes, and
Ions
• Isotopes
–Atoms of one element
protons
• Same number of _______
neutrons
• Different numbers of ________
masses
• Different ______
Parts of Atoms, Isotopes, and
Ions
• Ions
–________
Charged atoms that have gained
electrons
or lost ________
–Examples
• Iron loses 2 electrons
+2
Fe
• Chlorine gains 1 electron
-1
Cl
Page 104 #s 1-4
Read pages 105-109 and answer #s 9-15
on page 109