When a lithium atom becomes ionized its new electron configuration is 4 points the same as which element?

A. Ar
B. Mg
C. He
D. Fe

C. He

Explanation:

When lithium is ionized, its new electronic configuration is the same as that of a helium atom.

 Lithium is made up of 3 electrons with a configuration of:

                     2, 1

it has 1 electron in its outermost shell.

As a metal lithium will prefer to lose an electron due to its electropositivity.

    On losing an electron, it will have 2 electrons remaining

Now, Helium has 2 electrons and this makes it similar to Lithium that has lost one electron.

This makes Lithium isoelectronic with Helium.  

  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-