1. Where did the energy for this come from?
The nucleus.

2. Compare the 2 forces:
electromagnetic: Fe =
Is a force between two ___________________.
Attracts ________________ and repels _____________
___________________  ________range
Binds the ____ to the ___ within an atom
and bonds_____________ to other ____________
kq1q2/r2
charges
opposite q's
like q's
inverse square ∞ e- p
atoms
atoms
2. strong nuclear: Fsn
Is a force between two _________________
Always________________, even between_____________
_______________ force, but very ______________range
Holds the ____________________together
masses
attractive
protons
Strongest
short
nucleus

3. n =_____________
neutron
Ex: In a ____________
nucleus (___________):
small
helium
p =___________
proton
A close up of the 2 p: Fe
Fsn Fe
Fsn
Fsn ________________ > Fe ___________________
The _________________ wins  _____________nucleus
attraction
repulsion
attraction
stable
In addition, the ________________are also attracted
to the _______________ and to ________________ by the Fsn,
and they have ________ Fe repulsion.
neutrons
protons
each other no

4. Ex: In a ____________
nucleus (___________):
large
uranium 2 1
A close up of
protons 1 and 2: Fe Fe
Fsn 1 2
Fsn
The _______________ Fe is ______ the Fe in small nuclei.
BUT ______________Fsn is _____ the Fsn in small nuclei.
repulsive
<
attractive
<<<
Repulsion
____________wins  nucleus __________ and _________
unstable
decays.
For bigger nuclei: # of n _____ # of p. Why?
The n’s provide extra Fsn _____________w/o Fe ___________.
>
repulsion
attraction

5. The existence of the ______________force means that
there is an energy _____________ the nucleus called the
_______________ energy. __________________discovered that
this energy results in nuclei having more ____________ :
nuclear
within
bonding
Einstein
mass
Equivalence
The _______________________ of Mass and Energy
Ex. If 5.0 x 10-3 kg of mass is totally converted
to energy, how much energy will result?

7. The existence of the ______________force means that
there is an energy _____________ the nucleus called the
_______________ energy. __________________discovered that
this energy results in nuclei having more ____________ :
nuclear
within
bonding
Einstein
mass
Equivalence
The _______________________ of Mass and Energy
E = mc2
Ex. If 5.0 x 10-3 kg of mass is totally converted
to energy, how much energy will result?
E = mc2
(5.0 x 10-3 kg)
E =
(3.00 x 108 m/s)2
Or joules
E =
4.5 x 1014 kg·m2/s2

8. Notes:
If any object with ____________is converted completely
into pure ____________ , it will release a total of ________
joules. Think of mass as _________________ energy.
2. The term _______ is simply a ______________________
between mass m and energy E. The mass is not
moving at the ________________________ !
What will the graph
shown at right look like?
What quantity does the
slope represent?
mass m
energy
mc2
"congealed" c2
conversion factor
speed of light E m c2

9. splitting __________ nuclei into______________ ones
Ex 1: ____________
splitting __________ nuclei into______________ ones
used in __________________________
fission
bigger
smaller
nuclear reactors
before:
after: n
Ba-142 n
U-235 n
Kr-91 n
n U23592
Ba Kr n10
mass: =
(1)
charge:
0 +92 =
(0)

10. Is charge conserved?
Yes.
Is mass conserved?
YES: The # of nucleons (n and p) is __________________.
NO: The nucleons in Ba and Kr are ________________!!!
Yes and no.
the same
smaller
n U23592
Ba Kr n1o
_________mass!
more
____________mass!
less
The “missing” mass became _____________ ( E = mc2)
in the form of _______ of Ba, Kr, n and _________________.
This energy can be used 1/ _____________________________
in a ____________________ or 2/ ________________________
in an _______________________ .
energy KE
radiation
to heat water to steam
power plant
to kill people
atomic bomb

11. occurs when the neutrons produced
in one reaction are used to start new reactions
Chain reaction - _______________________________________
_______________________________________________________
U-235 n
________________– used to
____________the reaction
by ____________neutrons
control rods
limit
absorbing

12. First atomic bomb test: “Trinity” July 16, 1945,
at Alamogordo, New Mexico was set off by
imploding a subcritical mass of plutonium.
20 kilotons
of TNT
Today:

13. First military use of atomic weapons:
Hiroshima, Japan, August 6, 1945.

14. It contained 64 kg of uranium, of which less than a kilogram
Little Boy use U-235 H i r o s h m a
It contained 64 kg of uranium,
of which less than a kilogram
underwent nuclear fission,
and of this mass only 0.6 g
was transformed into energy

15. Nagasaki – 3 days later
Replica of Fat Man:
Method: implosion of Pu
Yield: 21 kilotons of TNT

16. New York Nuclear Power Plants:
Indian Point: 1970 MW
Nine Mile Point:
1756 MW
2 plants
in Oswego

17. James Fitzpatrick:
844 MW
near Oswego
R. E. Ginna:
498 MW
on Lake Ontario
east of Rochester

18.  combining ____________nuclei into _____________ ones
Fusion
Ex 2: _____________:
 combining ____________nuclei into _____________ ones
 powers _________________ and__________________
smaller
bigger
the stars
the Sun
before:
after:
H-2
He-3 n
H-2
H H21
He n10
mass =
charge =

19. Is charge conserved?
Yes.
Is mass conserved?
YES: The # of nucleons (n and p) is __________________.
NO: The nucleons in He32 and n10 are ________________!!!
Yes and no.
the same
smaller
H H21
He n10
_________mass!
more
____________mass!
less
The “missing” mass became _____________ ( E = mc2)
in the form of _______ of He and n and _________________.
The # of fusion power plants = ____ because it is difficult
to get the _______________ close enough so that the
_________________ attraction > electric _________________ .
energy KE
radiation
+ nucleons
strong nuclear
repulsion

20. Fission: How can both fission and fusion release energy?
Both result in less mass.
Fission:
Big nuclei can be fissioned to produce
energy b/c the products have less mass.

21. Fusion: Small nuclei can be fusioned to produce
energy b/c the products have less mass.
Notice: In both fission and fusion, iron (Fe) is the
lowest point on the curve. Its nucleons are smallest.

22. Number of fission reactors in the world:
Number of fusion reactors in the world:
439 reactors in 31 countries
150 naval vessels
6% of world’s energy
15% of world's electricity
In the US: 10% of fission energy
is supplied by using old Soviet warheads.

23. g _________ production: a gamma ray _____________ gets
“tickled” as it passes a nucleus. Its ____________
becomes a _____________ and _________________ pair
Pair
photon
energy
matter
antimatter
before:
after:
g-ray e- e+
nucleus
nucleus g e- + e+
The nucleus acts like a _________________ .
catalyst
The e+ is a _______________: the antiparticle of the e-
 same ____________ as the e-
 opposite ____________of the e-
positron
mass
charge

24. a. Compare the charge q before and after:= -1 +
+ 1
is conserved
 charge _______________________ .
b. Compare the mass before and after: =
me- +
me+ =
2me-
 mass _______________________ .
is not conserved
c. Compare "mass-energy" before and after:
Eph =
me-c2 +
me+c2
mass-energy _______________________ as long as
Eph has an energy at least equal to _________________
is conserved
(2me-)c2

25. Ex. Calculate the energy of the photon that is needed
to produce an electron and positron pair.
E = mc2
= 2mec2
= 2 (9.11 x kg)(3.0 x 108 m/s)2
= 1.64 x J
What is the frequency of the photon?
Eph = hf
1.64 x J = (6.63 x J s) f
f = x 1020 Hz

27. ________________________ is ALWAYS conserved,
even when _______________ is not. This is because mass
can be converted to ________________ and vice versa, but
neither __________nor ____________ can be destroyed.
Mass-energy
mass
energy
mass
energy
Ex: Is momentum p conserved?
before:
after:
pe-
pph
pe+
Rewrite these as: =
Momentum p is _____________________________ .
always conserved.

28. g ? Ex: Could a g-ray produce two electrons? e- + e- charge: = -1 += -1 +
- 1
 _________________ b/c charge _____________conserved.
Impossible
must be
In sum:
Momentum is _____________________ conserved.
Charge is _________________________ conserved.
Mass is ___________________________ conserved.
Energy is _________________________ conserved.
Mass-energy is ____________________ conserved.
Numbers ___ and ___ are ___________ conserved
when _______________ objects are involved.
always
always
sometimes
sometimes
always 3 4
often
bigger

29. 2g Pair ______________________: matter and antimatter
combine to form pure _________________ (photons).
annihilation
energy
after:
before: e-
g rays e+ 2g e- + e+
a. Compare the charge q before and after: -1 +
+ 1 = +
is conserved
 charge _______________________ .

30. b. Compare the mass before and after:
me+ +
me- = +
2me- =
is not conserved
 mass _______________________ .
c. Compare "mass-energy" before and after:
me-c2
me+c2
Eph
Eph + = +
2me-c2
2Eph =
mass-energy _______________________ as long as
Eph has an energy at least equal to ____________
is conserved
me-c2
Eph = me-c2
= (9.11 x kg)(3.0 x 108 m/s)2
= 8.20 x J