Advertisements
Advertisements
Question
A free atom of iron emits Kα X-rays of energy 6.4 keV. Calculate the recoil kinetic energy of the atom. Mass of an iron atom = 9.3 × 10−26 kg.
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
Advertisements
Solution
Here, energy of photon = E
E = 6.4 KeV = 6.4 × 103 eV
Momentum of photon
`= E/c = (6.4 xx 10^3)/(3 xx 10^8)`
`= 3.41 xx 10^-24 "kgm/sec"`
According to collision theory,
Momentum of photon = Momentum of atom
∴ Momentum of atom, P = 3.41 × 10−24 kgm/sec
Recoil KE of atom = P2/2M
`= ((3.41 xx 10^-24)^2 eV)/((20)9.3 xx 10^-26 xx 1.6 xx 10^-19) = 3.9 "eV"`
[1 Joule = 1.6 × 10−19 eV]
APPEARS IN
RELATED QUESTIONS
Name the phenomenon which shows the quantum nature of electromagnetic radiation.
Give the range of wavelength of the electromagnetic waves visible to us.
What do you understand by the invisible spectrum?
Name two sources, each of infrared radiations and ultraviolet radiations.
Why is exposure to X-rays injurious to health but not exposure to visible light, when both are electromagnetic waves?
An X-ray beam can be deflected
Consider a photon of a continuous X-ray coming from a Coolidge tube. Its energy comes from
Moseley's Law for characteristic X-ray is √v = a(Z − b). Here,
50% of the X-ray coming from a Coolidge tube is able to pass through a 0.1 mm thick aluminium foil. The potential difference between the target and the filament is increased. The thickness of the aluminium foil that will allow 50% of the X-ray to pass through will be
A certain element emits Kα X-ray of energy 3.69 keV. Use the data from the previous problem to identify the element.
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
Define the term "Intensity" in the photon picture of electromagnetic radiation.
Name the radiation of the electromagnetic spectrum which is used for the following:
To photograph internal parts of the human body and Give the frequency range
State three properties of ultra-violet radiation similar to visible light.
Give one use of electromagnetic radiation in Ultraviolet radiation.
Give one use of electromagnetic radiations in Infrared radiation.
Write two uses of the following radiation.
Gamma rays
Photons of an electromagnetic radiation has an energy 11 keV each. To which region of electromagnetic spectrum does it belong?
Identify the electromagnetic wave whose wavelength range is from about 10-12 m to about 10-8 m. Write one use of this.
Identify the part of the electromagnetic spectrum which:
- produces the heating effect.
- is absorbed by the ozone layer in the atmosphere.
- is used for studying crystal structure.
Write any one method of the production of each of the above radiations.
Name the electromagnetic radiation that has been used in obtaining the image below.
