Q3 of 94 Page 442

Calculate the mass of an α-particle. Its binding energy is 28.2 MeV.

We know that an alpha particle consists of two protons and two neutrons.

Mass of proton = 1.007276 u


Mass of neutron = 1.008665 u


Where u = 1.6605402 × 10-27 kg (Atomic mass unit)


Let the mass of the alpha particle be M


∴ Mass defect is ΔM,




Given, Binding energy = 28.2 MeV


Binding energy is also equal to


So,



[Note ]






Hence, the mass of an alpha particle is 4.0016u


More from this chapter

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1

Assume that the mass of a nucleus is approximately given by M = Amp where A is the mass number. Estimate the density of matter in kg m–3 inside a nucleus. What is the specific gravity of nuclear matter?

 2

A neutron star has a density equal to that of the nuclear matter. Assuming the star to be spherical, find the radius of a neutron star whose mass is 4.0 × 1030 kg (twice the mass of the sun).

 4

How much energy is released in the following reaction:

7Li + p → α + α.


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 5

Find the binding energy per nucleon of if its atomic mass is 196.96 u.