When chromium loses two electrons, its configuration changes to a. [ar]4s13d5. b. [ar]4s1. c. [ar]4s13d4. d. [ar]3d4.

Electronic configuration of cromium is  

Cr-[Ar]4s¹3d⁵  

When cromium loses two electrons it becomes Cr⁺².  

So its electronic configuration becomes,  

Cr⁺²-[Ar]3d⁴  

One electron will go from 4s orbital and one electron will go from 3d orbital.

So the answer here is D. [Ar]3d⁴ -because after losing 2 electrons electronic configuration of cromium becomes  [Ar] 3d⁴.

a  solution  is always transparent, light passes through with no scattering from solute particles which are molecule in size. the  solution  is homogeneous and does not settle out. a colloid is intermediate between asolution  and a  suspension. while asuspension  will separate out a colloid will not.

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be