Question

An element ‘x’ has 2 electrons in outermost orbit, ’y’ has 7 valence electrons.
Show the formation of compound between them and writeformula also. Will

this compound be soluble in water​

Answer 1

Explanation:

One of the elements with valence electrons 2 is Be.

So, I take the element 'x' as Be.

One of the elements with valence electrons 7 is F.

So, I take the element 'y' as F.

A compound formed between these two elements is BeF2.

BeF2 is soluble in water due to greater hydration energy of Be2+ ion as compared to the crystal lattice.

The other fluorides of alkaline earth metals are almost insoluble in water. Since on descending the group lattice energy decreases more rapidly than the hydration energy.