Atomic and Nuclear Physics Answers

What are the two radioactive elements are not found observable quantities in nature?

In Stern Gerlach experiment,why should one use neutral atoms instead of ions?If one performs the experiment with an atom of total angular momentum J,how many lines will be obtained?

Give one example of each of the following type of physical quantity:
(i) Dimensionless constant
(ii) Dimensional constant
(iii) Dimensionless variable
(iv) Dimensional variable

Find the apparent weight of a 18 kilogram lead block submerged in the dead sea.

120 atoms: 40 have decayed, what is the half life? What is it in years?

Velocity of an electron

what is fission?

The ratio of wavelength of a proton and electron of same energy will be?

Briefly explain properties of nuclear forces. Prove that they are charge independent and spin dependent

If all electromagnetic waves are made up of photons (discrete quanta), why don’t we hear the effect of each distinct packet of energy when we listen to a radio (which is being effected by a radio wave)?