Which of the following statements regarding spontaneous changes is false?A. Spontaneity is favored when heat is released. B. Spontaneity is favored when the dispersal of matter is increased. C. Spontaneous changes occur at a given state without any outside influence. D. Ice melting at 25°C is spontaneous primarily due to the increase in molecular disorder (dispersal of matter).E. All exothermic reactions are spontaneous.

Option (E) is the correct answer.

Explanation:

A spontaneous reaction is defined as the process which tends to occur on its own. And, a non-spontaneous reaction is defined as a process for the completion of which we have to provide certain conditions.

For example, ice melting at is spontaneous primarily due to the increase in molecular disorder (dispersal of matter). Also, melting of ice is taking place on its own without any external force.

It is not necessary that all exothermic reactions will be exothermic in nature.

Thus, we can conclude that the statement all exothermic reactions are spontaneous, is false.

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.