close

Вход

Забыли?

вход по аккаунту

?

Nuclear Chemistry in our World

код для вставкиСкачать
Atoms: Nuclear Interactions
Part Two:
Nuclear Radiation
1. What device was first used to detect
radioactivity?
пЃµ Geiger counter
2. Describe how a geiger counter works:
 when ionizing radiation enters the counter’s
tube, or probe, it causes the gas that is
stored their to become ions, now that the
gas has a positive charge, it can conduct
electricity, when it does this, the counter
registers a “count”. The units of measure
are counts per minute(cpm)
Geiger Counter
3. What kind of radiation can geiger
counters detect?
пЃµalpha, beta, gamma radiation
4. What is background radiation?
пЃµconstant quantity of natural
radioactivity present in the
environment
5. How do you factor it out when you are
measuring radioactivity?
пЃµsubtract the background radiation from
the cpm you get
6. What is a rad? What is another unit
that means the same thing?
пЃµradiation absorbed dose, Gray
7. What is a rem? What does it take into
account?
пЃµroentgen equivalent man-power of
radiation to cause ionization in human
tissue
8. How is rem calculated?
пЃµmultiply Rad by a unit of biological
damage
9. What are the two factors that
determine tissue damage?
пЃµthe density of ionization(number of
ionization per area) and the
dose(quantity of radiation received
пЃµDo
ChemQuandary 2 on Page 430:
“Why might radiation exposure
levels standards for some
individuals be different from those
for the general public? Why are
standards different for those who
are occupationally exposed?”
пЃµDo making decisions on page 430
10. Name some of the natural sources of
background radiation?
пЃµCosmic rays, radioisotopes in rock and
atmosphere
11. Name some of the human sources of
background radiation?
пЃµfallout from nuclear weapons testing,
increased exposure to cosmic rays due to air
travel, medical x-rays, radioisotopes released
from uses of nuclear technology
Sources of Ionizing Radiation
12. What is the estimated
background exposure in a year on
the average?
пЃµ135 mrem
13. What level of radiation is
considered safe for the average
person?
пЃµ170 mrem
Homework
пЃµHomework:
P 446-447: 1-3, 8
14. What sources of radiation do we
have a choice in whether we are
exposed to them or not?
пЃµX-rays and other medical
procedures
15. What happens if you are exposed
to a low level or radiation?
пЃµonly a very small number of
molecules are harmed and the body
can usually repair the damage
16. What happens if you are exposed
to a high level of radiation?
пЃµa lot of damage and the body may
not be able to repair it
17. What happens if your DNA in your cells
are damaged?
пЃµeither it kills the cell, causes it to make
protiens that it normally doesn’t make, or
causes it to divide and not know how to
stop
18. What are some diseases that are
supposedly caused by radiation damage?
пЃµLeukemia(cancer of the white blood cells),
anemia, heart related problems, and
cataracts
19. Are we safe from low levels of
radiation?
пЃµnot enough information to know for
sure
20. How many Mrems are we believed to
receive a year from natural sources?
пЃµ150 mrems
пЃµHomework:
P 446-447: 9-12
21. What is an alpha particle composed
of?
пЃµtwo protons and two neutrons, just like
the nucleus of a Helium ion He-4
22. How does an alpha particle compare
with a beta particle?
пЃµ8000 x larger but cannot penetrate very
far, a few cm of air can stop alpha,
alpha cannot even penetrate your skin
23. Where can alpha cause great
damage?
пЃµinside the body, in your blood or
organs(especially your lungs)
24. Give an example of a rxn where
an alpha is emitted:
пЃµ226Ra --> 4He + 222Rn
25. What are beta particles?
пЃµfast moving electrons emitted from the
nucleus during beta decay
26. How does it differ from alpha?
пЃµmuch smaller but because it is moving
so fast it can penetrate far deeper into
things, but because they are so small
they cannot do as much damage as
alphas
27. What exactly happens during beta
decay?
пЃµa neutron is transformed into a proton
and an electron, the proton stays in the
nucleus and the electron is ejected
becoming the Beta particle
28. Give an example of a rxn where a
beta is emitted:
пЃµ1n
-->
1 p
1
пЃµ210
82Pb -->
+ 0-1 e210
0 eBi
+
83
-1
29. How do these guys usually leave
the nuclei?
пЃµin an excited state
30. What usually is given off along
with the particles?
пЃµenergy in the form of gamma
radiation
31. How does Gamma compare
with alpha and betas?
пЃµit is just pure energy, not made
of particles, has the greatest
amount of penetration power
but because it has no mass, it
does not do as much damage
пЃµHomework:
13
P 446-447: 4, 5, 6,
32. What is a decay series?
пЃµnew isotopes that are created are often
they themselves radioactive and will
further decay. A decay series is a set of
radio-isotopes and what they
become(daughter isotopes). It is kind
of like a genealogy because you include
all the isotopes and what they become
until you end up with an isotope that is
not radioactive.
33. Describe the decay series of
Uranium:
пЃµHomework:
P 446-447: 7
Radiation Lab
QuickTimeв„ў and a
Sorenson Video decompress or
are needed to see this picture.
Radon in Homes
34. Since when have we been in contract
with Radon?
пЃµsince the beginning
35. When did the public become aware?
1980’s with the advent of the energy
efficient home
36. How does radon affect our homes?
пЃµseeps in through cracks in the
basement from the ground
37. How do old homes compare with
new homes when it comes to Radon
content?
пЃµthey have far less amounts of radon
38. How is it dangerous to us?
пЃµit or its daughter cells could be
breathed into our lungs where it will
undergo further decay producing
alphas
39. How do scintillation counters work?
пЃµ the probe contains a substance that emits
light when ionizing radiation strikes it, the
counter counts the sparks of light
40. How can Radiation workers know if they
have received too much radiation?
пЃµ they were badges that contain a substance
sensitive the ionizing radiation, the badges
are “read” periodically
41. What happens to worker if he is
exposed to too much radiation?
пЃµthe Federal Government sets limits to
how much radiation a worker can
receive in a year, if the worker exceeds
this limit, he may be assigned to other
jobs that will limit his exposure
Cloud Chamber Lab
QuickTimeв„ў and a
Sorenson Video decompress or
are needed to see this picture.
пЃµ Do
Ensuring Public Safety on Page 445
Документ
Категория
Презентации
Просмотров
3
Размер файла
1 382 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа