Advertisements
Advertisements
Question
Determine the distance of the closest approach when an alpha particle of kinetic energy 3.95 MeV approaches a nucleus of Z = 79, stops and reverses its directions.
Advertisements
Solution
Let 'r' be centre to centre distance between α-particle when α particle is at the stopping point then K = `1/(4piepsilon_0) ((Ze)(2e))/r`
Given: K = 3.95 MeV
= `3.95 xx 10^6 xx 1.6 xx 10^-19` J
⇒ `r = 1/(4piepsilon_0) (2Ze^2)/K`
= `(9 xx 10^9 xx 2 xx 79 xx (1.6 xx 10^-19)^2)/(3.95 xx 10^6 xx 1.6 xx 10^-19)`
= `(9 xx 2 xx 79 xx 1.6 xx 10^-19 xx 10^9)/(3.95 xx 10^6)`
= `576 xx 10^-16` m
`r = 5.76 xx 10^-14` m
APPEARS IN
RELATED QUESTIONS
The size of the atom in Thomson’s model is ______ the atomic size in Rutherford’s model.
Answer the following question, which help you understand the difference between Thomson’s model and Rutherford’s model better.
Keeping other factors fixed, it is found experimentally that for small thickness t, the number of α-particles scattered at moderate angles is proportional to t. What clue does this linear dependence on t provide?
Define the distance of closest approach. An α-particle of kinetic energy 'K' is bombarded on a thin gold foil. The distance of the closest approach is 'r'. What will be the distance of closest approach for an α-particle of double the kinetic energy?
In Geiger-Marsden experiment, actual results were ______.
The equation of trajectory of a projectile is given by y = `"x"/sqrt3 - "gx"^2/20`, where x and y are in metres. The maximum range of the projectile is:
A narrow beam of protons, each having 4.1 MeV energy is approaching a sheet of lead (Z = 82). Calculate:
- the speed of a proton in the beam, and
- the distance of its closest approach
The energy levels of a certain atom for first, second and third levels are E, 4E/3 and 2E, respectively. A photon of wavelength λ is emitted for a transition 3 `→` 1. What will be the wavelength of emission for transition 2 `→` 1?
Choose the correct option from the following options given below:
When alpha particles are sent through a thin gold foil, most of them go straight through the foil, because ______.
Why is the nucleus treated as stationary during scattering?
