Question

The half life of Pa – 218 is 3 minutes. What mass of a 16 g sample of Pa – 218 will remain after 15 minutes?

Solution

Correct option is

0.5 g

Since 15 minutes , the number of nuclei left after 15 minutes  of the original number. 

Therefore, the mass of 16 g sample left after 15 minutes

                            .

SIMILAR QUESTIONS

Q1

Cal to protons ever attract each other?

Q2

How much energy is released when one amu is wholly converted into energy?

Q3

In the equation     

           ,  

The correct symbol for X is

Q4

The kinetic energy of a 300 K thermal neutron is

Q5

The energy released by the fission of one uranium atom is 200 MeV. The number of fissions per second required to produce 3.2 W of power is

Q6

The binding energy of deuteron  is 1.15 MeV per nucleon and an alpha particle  has a binding energy of 7.1 MeV per nucleon. Then in the reaction 

             

the energy Q released is 

Q7

What is the rest mass energy of an electron?

Q8

After two hours  of the initial amount of a certain radioactive isotope remains undecayed. The half life of the isotope is  

Q9

The half life of a certain radio isotope is 10 minutes. The number of radioactive nuclei at a given instant of time is 108. Then the number of radioactive nuclei left 5 minutes later would be

Q10

A freshly prepared radioactive source of half life 2 h emits radiation of intensity which is 64 times the permissible safe level. The minimum time after which it would be possible to work safety with this source is