Well, when an atom attains a stable valence electron, it means that the outer electrons are complete and so cannot attain any more electrons. For the first shell, it is complete when it has 2 electrons, the second shell is complete when it has 8 electrons, all the other shells also have a particular number when complete. Anyway, i believe the answer is HYDROGEN because when HYDROGEN combines with another atom of HYDROGEN, the outer shell is completed. This is because HYDROGEN has only 1 electron. If the two HYDROGENS, which both have 1 electron combine, they make the electrons 2, which is complete for the first shell, HYDROGEN ends in the first shell. Since the electrons become 2, the shell is at stable valence. In all the other options, this happens; NEON- It has 10 electrons, 2 in the first shell and 8 in the second. So the the shells are already complete, so it can't bond with any thing, which is completely against the question. RADON- Radon has 86 electrons. HELIUM- Helium has 2 electrons, so the shell is already full, and cannot bond, so it goes against the question. The question says BY BONDING. So the answer is definitely 4) HYDROGEN Hope i helped. Have a nice day, by the way, i'm very sure it's hydrogen.
I take that the insects remain constant no matter what happens to the frogs (which the frogs eat presumably). So a constant food supply for the frogs is not the problem.
The line for the alligators increases over time. It their numbers increase, the frogs are in trouble. The alligators will pursue lunch with determined single mindedness and there are more of them around.
So the frogs should decrease. Their natural enemy is the alligator and alligators won't go after insects. It's not worth their time.
