Consider what you have learned in your astronomy class and this article about physical processes. what types of processes can emit gamma-rays? select all that apply. select all that apply. mutual annihilation of an electron and a positron proton-proton fusion reactions high speed collisions, near the speed of light photospheres of stars emission lines of oxygen million kelvin intergalactic gas

the awnser is group 12

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.