Answer:
Rb: [Kr] 5s
Step-by-step explanation:
Rb is element 37, the first element in Period 5.
It has one valence electron, so its valence electron configuration is 5s.
The noble gas configuration uses the symbol of the previous noble gas as a shortcut for the electron configurations of the inner electrons.
The preceding noble gas is Kr, so the electron configuration is Rb: [Kr] 5s.
Sodium is Highly reactive. It reacts with like everything
OK, its deff not the last one b/c all that trash just goes into the air, overwater farm land would kill crops (no help there), Ive never heard of heating water to kill excess bacteria. There is ,however, a new technique called Bioremediation which is the use of living organism to clean up a medium i.e. air,soil, water. It would seem the 2nd answer is correct.
A is the answer to the question you asked.