Transcript Document

Composition Book
Notebook
set-up
Page
1
Table of contents
Nuclear Processes
Standard 11:
The Nuclear Process
(chapter 25)
Chemistry.
Ms. Siddall.
Title page
vocabulary
Standard 11:The Nuclear Process
(chapter 25)
1
1
Vocabulary
1.
2.
3.
4.
5.
6.
7.
8.
Isotope
Radioactivity
Radioactive decay
Radioisotope
Transmutation
Fission
Fusion
Half life
9. Radiation
10. Ionizing radiation
11. Alpha particle
12. Beta particle
13. Positron
14. Gamma ray
15. Transuranium element
Title page
vocabulary
1. Isotope: an atom with….
Standard 11:The Nuclear Process
(chapter 25)
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1
Review & Preview
The atom.
Inside the nucleus Outside the nucleus
NUCLEONS
Neutron
Proton
mass
charge
charge = 1
=
0
= +1
electrons
charge mass
= -1
=0
notes
Date:
Topic:
Objective:
Parts of the
atom
Inside nucleus outside nucleus
2
1
Study question 1
• Complete the table
Charge
proton
neutron
electron
mass
Study questions
Date:
Topic:
Objective:
Study question 1
proton
neutron
Charge
+1
mass
Parts of the
atom
Inside nucleus outside nucleus
electron
2
1
Atomic symbol:
• Example: 14-carbon.
Protons & neutrons 
14
Protons 
C
6
* Atoms are ranked by number of protons
on the periodic table = atomic number
• Example: 235-Uranium
Protons & neutrons 
Protons 
235
U
92
Additional notes and questions
Date:
Topic:
Objective:
Study question 1
Charge
proton
neutron
+1
mass
Parts of the
atom
Inside nucleus outside nucleus
electron
Study question 2
Atomic
symbols
Example: 14-carbon
The atom is made up of three particles…. The
first particle is…
The atomic symbol describes the number of … 2
1
study question 2
1. What is the complete atomic
symbol for 25-Magnesium?
2. How many neutrons are in this
atom? (show your work)
Page summary
Date:
Topic:
Objective:
Study question 1
proton
neutron
Charge
+1
mass
Parts of the
atom
Inside nucleus outside nucleus
electron
Study question 2
Atomic
symbols
Example: 14-carbon
The atom is made up of three particles…. The
first particle is…
The atomic symbol describes the number of … 2
1
Isotope: atom with the same number
of protons but a different number of
neutrons.
• Example:
235
92 U
92 protons &
143 neutrons
238
U
92
92 protons &
146 neutrons
study question 3
• What are the similarities and
differences between a 14-Carbon
isotope and a 13-Carbon isotope?
Standard 11a:
The Strong Nuclear Force
The Strong Nuclear Force.
• holds nucleons together.
• much stronger than electromagnetic
repulsion.
• extremely short range
• the strongest force known (so far!)
NEWS FLASH: All atoms with more than
one proton must contain the same or
greater number of neutrons.
study question 4
• Explain how protons are held together
in the nucleus even though the positive
charges repel each other.
Standard 11b
Energy and Types of Nuclear Reactions
A Nuclear Reaction.
• Produces about 1 million times more
energy than a chemical reaction.
• energy released can be calculated using
E = mc2
m = mass
c = speed of light = 3x108 m/s
study question 5
1. Which is more powerful?
a. A chemical reaction
b. A nuclear reaction
2. How is the energy of a nuclear
reaction measured?
Fission:
• A large nucleus is hit with a small particle
and splits into two or more smaller atoms.
• examples: nuclear energy & nuclear bombs
(235-U is hit with a neutron)
Fusion:
• Two small particles collide to form one
larger particle
• Examples: thermonuclear bombs & the sun
(2 hydrogen atoms combine to form helium)
study question 6
Name the following processes:
1. Two small particles collide to form a
larger particle
2. A large particle breaks apart after
being hit by a small particle
Fission of Uranium in a nuclear reactor.
Nuclear
Fusion.
study question 7
1. Which reaction is used for
nuclear power?
2. Which is used in nuclear bombs?
3. Which powers the sun?
Radioactive Decay.
•All atoms have at least one radioisotope
(unstable isotope) that emits radiation.
•example = hydrogen.
3H
1H
 Radioisotope!
2H
Radioactive decay
Radiation
3H
 -1e + 3He
-1e
33He
H
Radiation
study question 8
• Which atoms have unstable
radioisotopes?
Unstable Isotopes
• Out of 1500 isotopes only 154 are stable
• Some isotopes take a fraction of a second
to decay, some take billions of years.
• All man made isotopes are radioactive.
– e.x. Rf, Db
– They do not exist in nature because
they have very short half lives.
study question 9
• Name 3 atoms that are not found in
nature.
Radioactive decay
• Parent isotope = radioisotope that decays
• Daughter isotope = result of parent
isotope decay (could also be radioisotope).
RADIATION
• Example:
238Pu 234U + 4He
parent daughter
study question 10
For the following reaction label:
1. The parent isotope
2. The daughter isotope
3. The radiation
3H
 3He + +1e
Standard 11c & 11d:Radiation & Effects.
There are 3 types of radiation:
1. Alpha decay α
• Produces alpha particle
= α = 4He (helium nucleus)
• Ionizing energy
• Short range
• Can be stopped with thick clothing or
thick paper
• Example: 240Pu  236U + 4He
study question 11
• Write the equation for the spontaneous
alpha decay of 238-U
2. Beta Decay: β
• Produces beta particle
= high energy electron
= β = -1e or +1e (positron)
• Ionizing energy
• Longer range
• Can be stopped with metal foil
• Example: 14C  14N + -1 β
study question 12
• Write the equation for 66- copper
undergoing spontaneous beta (-1e)
emission
3. Gamma decay: ɣ
– Produces gamma ray
= ɣ = high energy photon.
– Ionizing energy.
– Very long range.
– Nothing stops gamma rays entirely.
– Concrete or lead offer good protection.
– Example: 60Co  60Ni + -1e + ɣ
study question 13
1. Which is the most penetrating
form of radiation?
2. Why?
Standard 11f: Half life
• Half-Life = The time it takes for ½ of a
radioactive sample to decay.
• The rate of decay never changes.
• Example: carbon-14 has a ½ life of 5,715
years.
• After 5,715 years ½ of all 14-carbon
atoms have undergone radioactive decay
5715 years pass
Half-Life
Carbon dating
study question 14
• A body containing 0.25g 14-carbon is
discovered. How old is it? (a live person
contains 1.0g 14-carbon.)
Example: How much of a 100g sample of 222Rn
is left after 12 days? (½ life = 4 days)
• How many half-lives is that?
3
• After 4 days you have…
50g
• After 8 days you have…
25g
• After 12 days you have…
12.5g
study question 15
• 3-hydrogen has a half life of 12 years.
How much of a 20mg sample would be
left after 48 years?
Example: 1.00g 210-Po is re-examined
after 276 days. Only 0.25g remain.
What is the ½ life of 210-Po?
• How many ½ lives elapse?
• 1.00g  1 ½ life 
• 0.5g  1 ½ life  0.25g
• 2 ½ lives
• 2 ½ lives = 276 days
• 1 ½ life = 138 days
study question 16
• The ½ life of 238-Uranium is about 5
billion years. If approximately half of all
238-Uranium on earth has already
decayed, how old is the earth?