Download Ch 8 CK12 Test review on Radioactivity

Ch 8 CK12 Vocab & Test review
Physical Science
The center of an atom is it’s
____________
Nucleus
The nucleus is made of
Protons & Neutrons
An element with a different
number of neutrons than others
of its kind.
Isotope
Four fundamental forces:
1. Strong Nuclear Force
2. Electromagnetic Force
3. Weak Nuclear Force
4. Gravitational Force
Which force causes protons and
neutrons to be attracted to each
other in the nucleus?
Strong Nuclear force
When the strong force is not
strong enough, the nucleus can
decay, giving off matter and
energy. This is called ….
RADIOACTIVITY
The _______ of neutrons to protons is
related to the stability of the nucleus.
RATIO
More stable when neutron to proton ratio is 3:2.
Elements with >92 protons are all
___________________
synthetic
Scientist who discovered
radioactivity.
Henri Becquerel
Scientist who first coined the
term “Radioactivity”
Marie Curie
What and how did Becquerel
discover radioactivity.
He left U (Uranium) compound on
photographic plates in a lightless drawer and
the plates developed.
Which particle IDENTIFIES an
element?
Protons, neutrons or electrons?
PROTONS!
Three main types of nuclear radiation.
Alpha
Beta
Gamma
This particle is made of 2 protons
and 2 neutrons.
Alpha
This particle is the same as a
helium nucleus with a +2 charge.
Alpha
This particle can be stopped by a
piece of paper. They are the least
penetrating radioactive particle.
Alpha
This particle is the most massive. It
also is the most electric and exerts an
electric force on electrons in its path.
Alpha
Smoke detectors contain this type of
particle. (from radioactive
Americium)
Alpha
Changing one element into another
element through nuclear decay is
called...
Transmutation
Large nuclei (atomic # >83) are
radioactive because the nucleus is
___________ & _________
Large nuclei (atomic # >83) are
radioactive because the nucleus is
Large & unstable
This type of decay is caused by
the weak nuclear force. It occurs
when a neutron decays into a
proton and emits an electron.
BETA (minus)
This particle is faster than an
ALPHA particle. They can pass
through paper but are stopped
by aluminum foil.
BETA
This particle has the symbol
0e
-1
BETA
This particle is the most
penetrating form of radiation.
GAMMA
This particle has no mass and no
charge!
GAMMA
This particle requires lead or
concrete to stop it.
GAMMA
These particles are electromagnetic
waves with the highest frequencies
and shortest wavelengths in the
electromagnetic spectrum.
GAMMA
Which particle causes the least
biological damage to tissue.
GAMMA (because it passes
through tissue and produces
fewer ions because it has no
charge itself.)
What are the charges on the
following particles?
ALPHA
BETA
GAMMA
What are the charges on the
following particles?
ALPHA +2
BETA -1
GAMMA no charge! Zero! Nada!
A measure of the time required by
the nucleus of an isotope to decay is
_________. The time required for
half the nuclei of a sample to decay.
HALF LIFE
Radioisotope used to date plant
and animal remains.
Carbon-14
What percentage of radioactive
nuclei is left after 2 half-lives pass?
25 %
What percentage of radioactive
nuclei is left after 3 half-lives pass?
12.5 %
IF the half-life of iodine-131 is 8 days,
how much of a 5 gram sample is left
after 32 days?
32 days is 4 half-lives:
So 1/16 of the original number of nuclei left:
1/16 x 5g = 0.3g left
Determine the daughter nucleus
formed when a radon-222 emits
an alpha particle.
Polonium
222
218
4
Rn
Po
+
He
86
84
2
A ___________ uses alcohol
vapor to detect alpha or beta
particles.
Cloud chamber
A ___________ holds super
heated liquid under high
pressure.
Bubble chamber
A ___________ detects radiation by
producing an electric current when it
detects a charged particle. Produces
a clicking sound and intensity of
radiation is related to speed of clicks!
Geiger counter
Naturally occurring radiation. Comes
from rocks, soils, and atmosphere.
Background radiation
The process of splitting a nucleus
into several smaller nuclei.
Nuclear Fission
A series of fission reactions that
produces extra neutrons which
continue to split other nucleii
Chain reaction
The amount of material required
so that each fission reaction
produces approximately one
more fission reaction.
Critical mass
The process of joining two low
mass nuclei into one nucleus.
Nuclear Fusion
Where does fusion occur mostly?
And why?
Sun & Stars
because of high temperatures and huge gravitational
pressure able to squeeze nuclei together!
Which process, fission or fusion,
creates large amounts of energy
from a small amount of mass?
BOTH!
Two hydrogens combine for form helium.
This is an example of _______ ________
Nuclear Fusion
Uranium breaks down to form barium and
Krypton and 3 neutrons.
This is an example of _________ _______
Nuclear fission
(remember: fission is splitting)
Medical uses of radiation to tract
molecules or diagnose diseases in
organisms.
Tracers
Give an example of a medical
tracer.
Iodine-131 – used to detect disorders
of the thyroid gland in your neck!
A _______ ______ uses the energy
from controlled nuclear fission
reactions to generate electricity.
Nuclear reactor
Name 3 advantages of nuclear
power.
1. No air pollutants
2. No carbon dioxide (greenhouse gas)
3. Large amounts of energy (but is about as
efficient as fossil fuel process)
Name 2 disadvantages of nuclear
power.
1.
Radioactive waste that are hard to
dispose of
2. In event of accident, radioactive
exposure to environment
How are nuclear wastes disposed of?
1.
Ceramic containers within metal-alloy
containers and buried hundreds of
meters below the ground.
2. Can take thousands of years for this
waste to decay to safe levels.
Give two examples of major
nuclear accidents.
1. Chernobyl, Ukraine 1986
overheated reactor blew up
2. Japan – due to tsunami 2012
Give 2 advantages of nuclear
fusion
1. Uses hydrogen as fuel, and it is
abundant on Earth (in ocean!)
2. Product is helium, and it is not
radioactive and is chemically
unreactive!
Give the disadvantage of nuclear
fusion
1. Extreme temperatures required
for fusion to occur.
Look over your PowerPoint notes
and vocabulary!