Question

How many grays is this?Part A

A dose of 4.7 Sv of γ rays in a short period would be lethal to about half the people subjected to it.

Part b

What is the energy released in the fission reaction of the equation n+23592U→9440Zr+13952Te+3n? The atomic masses of 23592U, 9440Zr, and 13952Te are 235.043930 u, 93.906315 u , and 138.93473 u respectively, and the mass of a neutron is 1.008665 u.

Answer 1

A) 1 Sv is equivalent to 1 gray.

Therefore 4.7 Sv =4.7 grays.

The average person receives about 2.4 mSv per year from natural radiation.As a dose of 1 Sv causes acute radiation sickness, and a dose of 10 Sv is fatal.Therefore, a dose of 4.7 Sv of y rays in a short period would be lethal to about half the people subjected to it.

B) The energy released immediately after the fission process is equal to the energy equivalent of the mass lost in the fission process

Let mass of the reactants = (atomic mass of n )+(atomic mass of23592U)

                                          = 1.008665 + 235.043930

                                          = 236.052595

Let the mass of the products = (atomic mass of the 9440Zr ) + (atomic mass of the 13952Te) +

   (3 atomic mass of the n)

                                               =93.9063150 +138.934730+3.025995

                                               =235.867075

Dfference the masses = mass of the reactant - mass of the products

                                     =236.052595 - 235.867075

                                     =0.185520U

Energy released = Difference in the masses * 931 MeV

                            =0.185520 * 931 MeV

                             =172.71912 MeV