I think its A because some scientist from the Department of Physics of Northeastern University found out that is not a part of Dalton's atomic theory.
It states the fact, which we now know, that electrons are responsible for the chemical bonding. According to this theory, valency is the number of electrons present in the outermost energy shell of the atom. This energy shell is called valency shell.
The correct answer is 3.
A dynamic phase equilibrium is when a reversible reaction no longer changes its ratio of reactants to products. However, substances continue to move between the chemicals at an equal rate, which means the net change is 0. This is known as a steady state.
The density does not change because it is still the same liquid as before
