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Conceptual questions

Why is a PET scan more accurate than a SPECT scan?

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Isotopes that emit α radiation are relatively safe outside the body and exceptionally hazardous inside. Explain why.

Alpha particles do not penetrate materials such as skin and clothes easily. (Recall that alpha radiation is barely able to pass through a thin sheet of paper.) However, when produce inside the body, neighboring cells are vulnerable.

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Ionizing radiation can impair the ability of a cell to repair DNA. What are the three ways the cell can respond?

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What is the dose in mSv for: (a) a 0.1-Gy X-ray? (b) 2.5 mGy of neutron exposure to the eye? (c) 1.5m Gy of α exposure?

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Find the radiation dose in Gy for: (a) A 10-mSv fluoroscopic X-ray series. (b) 50 mSv of skin exposure by an α emitter. (c) 160 mSv of β and γ rays from the 40 K in your body.

Gy = Sv RBE : a. 0.01 Gy; b. 0.0025 Gy; c. 0.16 Gy

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Find the mass of 239 P u that has an activity of 1.00 μCi .

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In the 1980s, the term picowave was used to describe food irradiation in order to overcome public resistance by playing on the well-known safety of microwave radiation. Find the energy in MeV of a photon having a wavelength of a picometer.

1.24 MeV

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What is the dose in Sv in a cancer treatment that exposes the patient to 200 Gy of γ rays?

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One half the γ rays from 99 m T c are absorbed by a 0.170-mm-thick lead shielding. Half of the γ rays that pass through the first layer of lead are absorbed in a second layer of equal thickness. What thickness of lead will absorb all but one in 1000 of these γ rays?

1.69 mm

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How many Gy of exposure is needed to give a cancerous tumor a dose of 40 Sv if it is exposed to α activity?

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A plumber at a nuclear power plant receives a whole-body dose of 30 mSv in 15 minutes while repairing a crucial valve. Find the radiation-induced yearly risk of death from cancer and the chance of genetic defect from this maximum allowable exposure.

For cancer: ( 3 rem ) ( 10 10 6 rem · y ) = 30 10 6 y , The risk each year of dying from induced cancer is 30 in a million. For genetic defect: ( 3 rem ) ( 3.3 10 6 rem · y ) = 9.9 10 6 y , The chance each year of an induced genetic defect is 10 in a million.

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Calculate the dose in rem/y for the lungs of a weapons plant employee who inhales and retains an activity of 1.00 μ Ci 239 Pu in an accident. The mass of affected lung tissue is 2.00 kg and the plutonium decays by emission of a 5.23-MeV α particle. Assume a RBE value of 20.

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Additional problems

The wiki-phony site states that the atomic mass of chlorine is 40 g/mol. Check this result. Hint: The two, most common stable isotopes of chlorine are: 17 35 Cl and 17 37 Cl . (The abundance of Cl-35 is 75.8 % , and the abundance of Cl-37 is 24.2 % .)

atomic mass ( Cl ) = 35.5 g/mol

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A particle physicist discovers a neutral particle with a mass of 2.02733 u that he assumes is two neutrons bound together.

(a) Find the binding energy.

(b) What is unreasonable about this result?

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A nuclear physicist finds 1.0 μ g of 236 U in a piece of uranium ore ( T 1/2 = 2.348 × 10 7 y ). (a) Use the decay law to determine how much 236 U would had to have been on Earth when it formed 4.543 × 10 9 y ago for 1.0 μ g to be left today. (b) What is unreasonable about this result? (c) How is this unreasonable result resolved?

a. 1.71 × 10 58 kg ; b. This mass is impossibly large; it is greater than the mass of the entire Milky Way galaxy. c. 236 U is not produced through natural processes operating over long times on Earth, but through artificial processes in a nuclear reactor.

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Questions & Answers

what is bohrs model for hydrogen atom
Swagatika Reply
what is the value of speed of light
Propessor Reply
1.79×10_¹⁹ km per hour
what r dwarf planet
Sivalakshmi Reply
what is energy
Isiguzo Reply
কাজের একক কী
কাজের একক কী
friction ka direction Kaise pata karte hai
Rahul Reply
friction is always in the opposite of the direction of moving object
A twin paradox in the special theory of relativity arises due to.....? a) asymmetric of time only b) symmetric of time only c) only time
Varia Reply
b) symmetric of time only
fundamental note of a vibrating string
fasoyin Reply
every matter made up of particles and particles are also subdivided which are themselves subdivided and so on ,and the basic and smallest smallest smallest division is energy which vibrates to become particles and thats why particles have wave nature
what are matter waves? Give some examples
mallam Reply
according to de Broglie any matter particles by attaining the higher velocity as compared to light'ill show the wave nature and equation of wave will applicable on it but in practical life people see it is impossible however it is practicaly true and possible while looking at the earth matter at far
a centeral part of theory of quantum mechanics example:just like a beam of light or a water wave
Mathematical expression of principle of relativity
Nasir Reply
given that the velocity v of wave depends on the tension f in the spring, it's length 'I' and it's mass 'm'. derive using dimension the equation of the wave
obia Reply
What is the importance of de-broglie's wavelength?
Mukulika Reply
he related wave to matter
at subatomic level wave and matter are associated. this refering to mass energy equivalence
it is key of quantum
how those weight effect a stable motion at equilibrium
Nonso Reply
how do I differentiate this equation- A sinwt with respect to t
Evans Reply
just use the chain rule : let u =wt , the dy/dt = dy/du × du/dt : wA × cos(wt)
I see my message got garbled , anyway use the chain rule with u= wt , etc...
de broglie wave equation
LoNE Reply
vy beautiful equation
what is electro statics
fitsum Reply
when you consider systems consisting of fixed charges
hi ma new

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Source:  OpenStax, University physics volume 3. OpenStax CNX. Nov 04, 2016 Download for free at http://cnx.org/content/col12067/1.4
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