Answer:
THE CORRECT ANSWER IS COMMAND.HOPE IT HELP YOU
c) the salt solubility decreases with temperature.
Salts usually dissolve in water at a given temperature. When water cannot dissolve anymore salt at that same temperature, it is known as a saturation point. With most substances the solubility increases with increase in temperature. Same is the case for a salt like potassium nitrate. With increase in temperature the ability of it to dissolve in water increases. And so with decrease in temperature, the solubility decreases.
Answer:
n=6 to n=3 (B)
Explanation:
Energy of an electron present in the 
orbit is directly proportional to 
.Hence a transistion from one orbit to another orbit emits an energy proportional to the difference of their squares of the orbits. that is if an electron travels from orbit n1 to orbit n2 then it emits an energy corresponding to 
.So in the above question the highest energy emission occurs when an electron moves from n=6 to n=3.(Highest difference of energy levels).
A second order reaction varies with the square of the concentration of the reactant. Therefore, halving the concentration will reduce the rate of reaction by a factor of 4.
The answer is E.
