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.
Displacement reaction is a chemical reaction in which a more reactive element displaces a less reactive element from its compound. Both metals and non-metals take part in displacement reactions. Example : Reaction of iron nails with copper sulphate solution.
Answer:
Well, one is if heat is absorbed by the system from the surroundings, the system gains heat from the surroundings and so the temperature of the surroundings decreases.
Explanation:
Answer:
The molecular formula of an ascenapthalene is 
Explanation:


where,
=Elevation in boiling point = 
Mass of acenapthalene = 0.515 g
Mass of
= 15.0 g = 0.015 kg (1 kg = 1000 g)
= boiling point constant = 3.63 °C/m
m = molality
Now put all the given values in this formula, we get


Let the molecule formula of the Acenapthalene be ![C_{6n]H_{5n}](https://tex.z-dn.net/?f=C_%7B6n%5DH_%7B5n%7D)

n = 2.0
The molecular formula of an ascenapthalene is 
It is easiest to tell if a solution is saturated if there is residue on the bottom. If it crystallized, the solution is saturated. If it is a supersaturated solution, there will not be crystallization unless more of the solute is added, at which point all of it will crystallize.