Download CP NT Ch. 4 and 25 v2

Structure of the Nuclear Atom
I.
The _________
A. The ________ is the smallest particle of an element that retains its ______________ of
the element.
II. History of the Atom
A. Democritus
1. Democritus (460 B.C. – 370 B.C) was the first to suggest the ____________ of atoms
2. Democritus believed atoms were _______________ and _________________
B. Dalton’s Atomic Theory
1. All elements composed of __________________ particles called atoms
2. Atoms of the same element are _______________
3. Atoms of different elements can physically mix together or _______________
combine in simple whole-number ratios to form ________________.
4. Chemical ______________ occur when atoms are separated, joined, or rearranged.
lll. Size of the Atom
A. The radii of most atoms range from ____________m to ___________m
B. Individual atoms are observable with instruments such as a scanning tunneling
__________________.
Question Time
What is an atom?
Who is Democritus?
What are the four ideas of Dalton’s Atomic Theory?
What is the size of most atoms?
What do scientists use to see an atom?
lV. Atoms and Their Charges
A. Atoms have ____________electrical charge, they are electrically _____________
B. Electric charges are carried by particles of matter (_____________ particles)
C. Electric charges always exist in ___________________multiples. (no fractions)
D. When a given number of _____________ charged particles combines with an equal
number of _______________ charged particles, an electrically ___________ particle is
formed
V. Subatomic Particles
A. There are three kinds of subatomic particles. These particles make up the atom.
1. ___________ (negative)
2. ___________ (positive)
3. ___________ (neutral)
B. Electrons
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1. Electrons are ______________ charged
2. One electron carries __________ of negative charge
3. Has a mass of 1/1840 of a ___________________
4. Symbol for and electron is ______________
C. Protons
1. Protons are _____________ charged subatomic particles
2. Each proton has a mass about 1840 times that of an __________
3. Symbol for a proton is __________
D. Neutrons
1. Neutrons are subatomic particles with ______________
2. Has a mass equal to that of a ____________
3. Symbol for a neutron is ____________
Question Time
What charge are atoms?
Are there fraction of charges?
What if there were nine positively charged particles and eight negatively charged particles,
what would the net charge of the atom be?
What are the three subatomic particles and what are their charges?
What is the mass of an electron compared to a hydrogen atom?
What is the mass of a proton compared to a neutron?
Vl. J.J. Thompsons’s Plum Pudding Model
A. When subatomic particles were discovered, scientist wondered how these particles
were put together in an atom.
B. J.J. Thompson thought that ____________ were evenly distributed throughout. An
atom was filled uniformly with _____________ charged material called the “plumpudding” model or “chocolate cookie dough” model
Vll. Rutherford’s Gold Foil Experiment
A. In _______ Ernest Rutherford wanted to study the structure of the atom as well. The
plum-pudding model was the prevailing theory back then
B. In his experiment he used alpha particles, which are _________ atoms that have lost
their two electrons.
C. Then, directed the alpha particles at a very thin sheet of gold foil. The particles
should have passed easily through the gold with a slight deflection due to the
___________ charge thought to be spread out in the gold atoms
D. The great majority of alpha particles passed straight through the gold atoms, without
______________
E. A small fraction of the alpha particle bounced off the gold foil at _______ angles.
F. Based on the experimental results Rutherford suggested that the atoms were mostly
__________________, but had a _________________called the _______________.
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G. Gold Foil Experiment Conclusion
1. All the ____________ charge and all the ________ of the atoms was concentrated
in a small region called the ____________
2. “This is almost as incredible as if you fired a 15-inch shell at a piece of tissue
paper and it came back and hit you.”
Vlll. The Nuclear Atom
A. The nucleus is the central core of an atom
1. composed of __________ and ____________.
B. The nucleus is much smaller than the atom, yet contains most of its _______
C. The __________ are distributed around the nucleus
1. occupy almost all the ___________ of the atom
2. Most of the atom is made up of ___________________.
lX. Fun Facts
A. The volume of a hydrogen nucleus is a trillion times smaller than the volume of a
hydrogen atom, yet the nucleus contains most of the mass.
B. If the nucleus (proton) of a hydrogen atom were as large as the width of a human
thumb, the electron would be on the average about one kilometer away in a great
expanse of empty space.
Question Time
What is the plum-pudding model and who thought of it?
Is the plum-pudding model correct?
What happened in the gold foil experiment?
What did the gold foil experiment prove?
Where is the positive charge located in the atom?
What contains most of the mass of the atom?
What occupies most of the volume of the atom?
What is the atom is mostly made up of?
I.
How Atoms Differ
Properties of Subatomic Particles
Particle
Symbol
Electron
e−
Proton
or
p+ or
Neutron
no or
Location
Relative
Charge
Relative
Mass
Actual Mass (g)
In the space
surrounding the
nucleus
1-
1/1840
9.11 ×10−28
In the nucleus
1+
1
1.673 ×10−24
In the nucleus
0
1
1.675 ×10−24
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II.
Atomic Number
A. The atomic number is the number of _________ or electrons in a __________ atom
B. Remember that atoms are neutral thus:
1. Atomic number = Number of __________ = number of _____________
C. Each _____________ has a unique number of protons
D. The periodic table is organized by increasing _____________ (number of protons)
E. Only protons determine the type of atom present and will never change for an
_____________.
Question Time
• What does the atomic number represent?
• Why are there an equal number of protons and electrons in a neutral atom?
• How many protons and electrons are in aluminum (Al)?
• An atom contains 28 protons, what element is it?
How many electrons does it have?
• How is the periodic table organized?
• What subatomic particle determines the type of element?
III. Isotopes and Mass Number
A. Isotopes are atoms of the same element that have the same number of ___________
but different number of _____________
B. Mass number represents the sum of the number of _________ and ___________ in the
nucleus
C. So, # of neutrons = ______________ – ______________
IV. Representing Isotopes
A. In Ag-107, the 107 represents the mass number (neutrons + protons)
B. In Ag-109, the 109 represents the mass number (neutrons + protons)
Question Time
• What are isotopes?
• What is the mass number?
• What is the mass number in carbon-14?
• What is the mass number and atomic number in
Fe?
• How many protons, neutrons, and electrons are in potassium-41, whose symbol is K?
• How many protons, electrons, and neutrons are in Ne?
• What is the difference between hydrogen ( H), deuterium (
H), and tritium (
H)?
V. Atomic Mass
A. The mass of an atom is so small it is difficult to work with, so chemists have
developed an ______________________ to compare all the masses to
B. The standard is the atomic mass unit (amu) is defined as _______ of the mass of a
_______________ atom
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C. If the mass of an element is not close to a whole number, it is because the atom has
several ______________
D. The atomic mass is the weighted average of the _______________ of that element.
VI. Example
A. Silver has two naturally occurring isotopes. Ag-107 has an abundance of 51.82% and
mass of 106.9 amu. Ag-109 has a relative abundance of 48.18% and a mass of 108.9
amu. Calculate the atomic mass of silver.
Question Time
• Rubidium is a soft, silvery-white metal that has two common isotopes,
Rb and
85
87
Rb. If the abundance of Rb is 72.2% and the abundance of Rb is 27.8%, what is the
average atomic mass of rubidium?
VII. Vocabulary to Know
A. Atomic #- same # of protons & electrons
B. Mass #-protons + neutrons
written 2 ways: Carbon-14 or
C
C. Isotopes-same # of protons, different # of neutrons
D. Atomic mass-weighted average mass
Types of Radiation and Unstable Nuclei
I.
Chemical and Nuclear Reactions
A. Chemical reactions only involve an atom’s ___________
B. Nuclear reactions involve changing an atom’s ____________
C. ___________ reactions release much more energy than ___________ reactions
1. about a million times more energy
D. Unlike chemical reaction, nuclear reactions are not affected by ______________,
pressure, or a ____________.
II.
Nuclear Vocabulary
A. ______________ – the process of emitting radiation.
B. _____________ - rays and particles emitted by a radioactive source.
C. _____________ – isotopes of atoms with unstable nuclei and emit radiation to obtain a
more stable nuclei
D. Radioactive _________ - Unstable nuclei losing energy by emitting radiation in a
spontaneous process.
E. _____________ – refers to both protons and neutrons
Question Time
• What is the difference between a chemical reaction and a nuclear reaction?
• Which type of reaction is affected by temperature, pressure, and a catalyst?
• Which type of reaction releases more energy?
• What is radiation?
• What is radioactivity?
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V.
A.
B.
C.
D.
E.
F.
What is a radioisotope?
What is radioactive decay?
What is a nucleon?
Which Isotopes are Radioactive?
Small Nuclei - Atoms which contain up to 20 protons (up to Calcium) are usually
____________.
Large Nuclei - Larger nuclei tend to be radioactive. All nuclei with _____ or more
protons (Polonium and up) are radioactive. For example, all isotopes of Uranium are
radioactive.
Atoms with more neutrons than protons - There are radioactive nuclei that have
less than 84 protons. These nuclei have more neutrons than protons. For example,
Carbon-12 (___ protons and ____neutrons) is stable, while Carbon-14 (____ protons
and _____ neutrons) is radioactive.
Why Does an Atom Undergo Radioactive Decay?
Radioactive atoms emit radiation because their nuclei are ____________.
The stability of the nucleus depends on the neutron to proton __________
Neutrons vs. protons graph stable nuclei found in a region called the
_________________________________
Types of Radiation – ___________ Radiation
____________ radiation deflect toward the negatively charged plate
Alpha particles contain _____ protons and ____ neutrons (A helium nucleus)
Blocked by paper
Least penetrating form of radiation (only travels a few centimeter in the air)
Carry _______charge
Symbolized by He or
α
VI.
A.
B.
C.
D.
E.
F.
Types of Radiation – ________ Radiation
_______ radiation deflect toward the positively charged plate
Carry ______ charge
Beta particles are fast moving ___________
Blocked by metal foil or wood
Medium penetration power (travels a few __________ in the air)
Symbolized by e or β
VII.
A.
B.
C.
D.
E.
F.
Types of Radiation – Gamma rays
Gamma rays are high energy radiation that possess ________________.
Possess ____ electrical charge and are not deflected by ___________ or electrical fields.
Not completely blocked by lead or concrete
The most penetrating type of radiation
Carry ______ charge
Symbolized by
γ
•
•
•
III.
A.
B.
C.
IV.
A.
B.
C.
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VIII. Positron Emission
A. ___________ – A particle with the same mass as an electron but opposite charge.
B. Symbolized by
e or
β
C. C → ______
+
e
IX. Electron Capture
A. Electron capture occurs when a _________ of an atom draws in a surrounding electron.
B.
Rb
+
e →
_______
Question Time
• Which elements are radioactive?
• Why does an element undergo radioactive decay?
• What makes a nucleus unstable?
• What is the band of stability?
• What does an alpha particle also known as?
• Is an alpha particle positive or negative?
• What blocks alpha particles?
• Is a beta particle positive or negative?
• What blocks beta radiation?
• Is a gamma ray positive or negative?
• What blocks gamma rays?
X.
Electrostatic Force
A. Electrostatic force is when like charges ________ and opposite charges ___________.
XI. Strong Nuclear Force
A. All nuclei except H atoms consist of neutrons and two or more protons. Since
protons are _________, the two positive charges should ________ because of
electrostatic repulsion.
B. The protons do not repel each other because of the strong ___________ force.
C. The strong nuclear force or nuclear force is an attractive force that acts between all
_______________________ that are extremely close together. It keeps the ___________
together.
Question Time
• What is an electrostatic force?
• What happens when two positive charges are close together?
• What is the strong nuclear force?
• Remember Mass Number and Atomic Number
XII. Writing and Balancing Nuclear Equations
A. In a balanced nuclear equation, _______ numbers and _______ numbers are conserved.
B. Example
Th 
Ra +
He
**Notice the mass numbers and atomic numbers add up to the same on both
sides of the equation
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Question Time
•
Zr 
•
Po 
• ? 
Rn
•
Ca 
•
Cm 
e
+ ?
He + ?
+ He
e + ?
He + ?
Transmutation
I.
Transmutation
A. The ________________ of one element to another element.
B. All nuclear reactions are transmutation reactions except for _________ emission
ll.
Induced Transmutation
A. Before 1919, transmutation only occurred ____________
B. In 1919 ________________ was the first to induce (cause) transmutation.
C. He proved that nuclear reactions can be produced artificially.
D. Induced transmutation can occur by bombarding an atom with _______ particles,
protons or neutrons.
III. Transuranium Elements
A. Elements with atomic number above _______.
B. All transuranium elements undergo transmutation
C. None of the transuranium elements occur in __________ and have been produced
through induced transmutation.
Question Time
• What is transmutation?
• Which reactions are transmutation reactions?
• What is induced transmutation?
• Before Rutherford, how could an element undergo transmutation?
• What are transuranium elements?
IV. Half-life
A. The time required for one-half of a radioisotope’s nuclei to decay into its ____________
B. After each half-life, _______ of the ______________ radioactive atoms have decayed into
atoms of a new element
C. Amount remaining = (initial amt)(1/2)n
1. n= ___________________
Question Time
• Scientists start with 50.0 g sample of a radioisotope. How much is left after four
half-lives?
• Iron-59 is used in medicine to diagnose blood circulation disorders. The half-life of
iron 59 is 44.5 days. How much of a 2.000 mg sample will remain after 133.5 days?
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V. Carbon-14 Dating
A. Carbon 14 dating is the process of determining the _______ of artifacts that were once
part of a living organism by measuring the amount of _____ remaining in that artifact
B. Carbon-14 is radioactive and undergoes ______ decay. It has a half-life of ___________
VI. Carbon-14
A. 14C evenly spread in the Earth’s _____________
B. Plants incorporate 14C into their structure that matches the level in the ______________.
C. When an organism dies, 14C declines at a known rate. (____________of C-14 =
________ years)
D. Comparing the _______________ 14C fraction of a sample to that expected from
atmospheric 14C allows the age of the sample to be _______________.
E. Dates carbon-bearing materials up to ___________ years.
Question Time
• What is radiochemical dating?
• How does carbon-14 dating work?
VII. Radioactive Glassware
A. http://www.dangerouslaboratories.org/rglass.html
Fission and Fusion of Atomic Nuclei
I.
Nuclear ___________
A. ____________ - The splitting of the nucleus into fragments (division)
B. Uranium-235 is struck by a neutron and forms _________, ___________ , and additional
neutrons.
II.
Chain Reaction
A. Nucleus captures a __________ and splits into fragments and produces three neutrons
B. ___________ start a new reaction
C. Critical mass
1. The minimum ______ required to support a self-sustaining ______ reaction
III. Nuclear ________
A. ________ - combining atomic nuclei to produce a nucleus of greater mass
B. the nuclei of lighter elements (such as hydrogen) are fused together at extremely
high ________________ and _______________ to form heavier elements (such as helium)
C. Fusion reactions release more _____________ than fission reactions
D. Capable of releasing large amounts of energy
E. Requires extremely high energies to ____________ and sustain
F. _________ is powered by fusion
Question Time
• What is fission?
• What products are formed in the fission of uranium?
• What is a chain reaction?
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What is critical mass?
What is fusion?
Where do we find fusion?
Nuclear Binding Energy
The energy required to break a nucleus into its individual __________ and ___________
Energy released in a _________ reaction is much greater than in ___________
reactions
V. Mass Defect
A. The mass of the nucleus is always ___________ than the sum of the masses of
individual protons and ___________.
B. The difference in mass has been converted to ____________
C. The energy can be calculated using ____________
Question Time
• What is the nuclear binding energy?
• Which releases much more energy nuclear or chemical reactions?
• What is the mass defect?
• What equation can be used to calculate the mass defect?
VI. Nuclear Reactors
A. The purpose of nuclear reactors is to keep the ___________________going without
letting it get out of control
VII. Bombs
A. Atomic Bomb
1. Uses __________
2. Uses enriched uranium-235 or ___________
3. Nagasaki and ______________
B. Hydrogen Bomb
1. Uses _________
2. _________ time more powerful than atomic bomb
3. Uses deuterium ______ and tritium _______
Question Time
• What is the purpose of nuclear reactors?
• Which is more powerful, an atomic or hydrogen bomb?
•
•
•
IV.
A.
B.
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