Questions

Colored aqueous solutions are a characteristic of transition compounds.

The only transition compound in the above choices is CrCl3.

Cr is a transition element.

The Arjuna Awards are given by the Ministry of Youth Affairs and Sports, Government of India to recognize outstanding achievement in sports. Started in 1961, the award carries a cash prize of ₹ 500,000, a bronze statue of Arjuna and a scroll.

Let that something be 'x'

From the given data,

x + x/5 = 21

5x + x/5 = 21

6x = 21 x 5

=> x = 17.5

Hence, that something is x = 17.5.

When atoms react they do so in order to reach the lowest energy, which is the most stable. The electrons orbitals will overlap in the way that reduces the energy the most. Orbitals of similar energy will produce the greatest stabilisation.The answer you gave isn't the whole story, it depends what species is reacting with what. The effective nuclear charge on the atom will affect the energy of the valance electrons.

Hence, the reactivity of an atom arises from the existence of unpaired electrons in the valence shell.