. As velocity
kinetic energy
and potential energy

Consider an object of mass m is made to fall freely from a height h. At a start, the potential energy = mgh and kinetic energy = zero because its velocity is zero. Total energy of the object = mgh. As it falls, its potential energy will change into kinetic energy.

Explanation:

one negative thing it that it can kill water animals. another negative thing is it can cause the destruction of ecosystem. one way water pollution can be reduced is to conserve energy.

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.