14 A teacher gives her students a paper plate, glue, 10 black beads (electrons), 10 blue beads (neutrons) and 10 red beads (protons). The students are to glue the beads onto the
paper plate to construct an atom. One student chooses to construct Magnesium and finds
out that he doesn't have enough beads. How many more beads of each color does he need
to correctly construct the atom?
A.2 black, 2 blue, 2 red
B.1 black, 1 blue, 1 red
C.3 black, 2 blue, 1 red
D.3 black, 3 blue, 3 red

i'm assuming that the correct answer is indeed the first one/ "a"..

  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-