Answer:
The configuration of the atom would be 2-8-2.
Explanation:
Any atom of an element combines with other element to complete its octet and become stable.
The electron configuration of the given atom is 2-8-6. That means the atom has 6 electrons in its outermost shell. To become stable the atom should have 8 electrons in its outermost shell. The given atom has 6 electrons so it either lose 6 electrons or gain 2 electrons to complete its octet.
But we know the atom having 5,6,7 electrons in its outermost shell they do not lose, they gain either 3 or 2 or 1 electrons to complete its octet.
So we say that atom with the electron configuration 2-8-6 bond with the atom having electron configuration 2-8-2.
Answer : Yes, a precipitate form when a solution of calcium chloride and a solution of mercury(I) nitrate are mixed together.
The net ionic equation will be,

Explanation :
In the net ionic equations, we are not include the spectator ions in the equations.
Spectator ions : The ions present on reactant and product side which do not participate in a reactions. The same ions present on both the sides.
The given balanced ionic equation will be,

The ionic equation in separated aqueous solution will be,

In this equation,
are the spectator ions.
By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.
The net ionic equation will be,

Water would not expand when it freezes.<span> </span>
To determine the expected pH of the resulting solution of the following substances, create a balanced chemical equation of their ionization in water:
HI
HI + H2O ---> H+ + I-
It completely dissociates into H+ and I-. Due to the presence of the Hydronium Ion, the solution is acidic.
KBr
KBr + H2O ----> HBr + KOH
The salt KBr is formed by a strong base and a weak acid, therefore, the solution it forms with water is basic.
LiOH
LiOH + H2O ----> Li+ + OH-
It dissociates completely in water, turns into Li+ and OH-. Due to the presence of Hydroxide Ion, the solution becomes basic.
It's melting, so solid to liquid