HELP!! Which of the following statements best explains why the atomic radius decreases from left to right across a period?
A.
The number of neutrons in an atom increases from left to right across a period, and they pull the valence electrons inward with greater force.
B.
The number of electrons decreases from left to right, so the electron cloud occupies a smaller volume.
C.
The charge of the nucleus of an atom increases from left to right across a period, so the valence electrons are pulled inward with greater force.
D.
The number of energy levels decreases from left to right, so the electron cloud occupies a smaller volume.

  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-

i don't see a text, but i am gonna assume this *orbit* the curved path, usually elliptical, described by a planet, satellite, spaceship, etc., around a celestial body, as the sun.

confused

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