Select the correct description of atomic structure. * A. Protons and electrons are located in the nucleus.
B. Protons and neutrons are located in the nucleus and electrons circle.
C. Atoms are in the nucleus and electrons circle.
D. Electrons and neutrons are located in the nucleus and protons circle.

you either don't have the answers wrote out correctly or none are correct but b looks like closest answer

Explanation:

protons are positive and rest in the center with neutrons electrons (like the name suggests) go in the electron cloud (or circle)

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-

the earth would become to overheated and everything alive on it will eventually die from overheating. plants will eventually die as well, water will evaporate, and it will be nothing but a hot planet without anything living on it.