Which water sources contribute to a river system? check all that apply.

groundwater
lakes
rivers
streams
watersheds

Explanation:

Larger networks of streams, lakes, rivers etc describe the river system as there are all part of a river's network.

Rivers, streams, and ground water move across the land and thus they contribute to the river system. Whereas a lake is defined as a large area of water which is surrounded by land and does not really contribute to river system.

Therefore, we can conclude that groundwater, rivers, and streams are the water sources that contribute to a river system.

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.