To find the number of neutrons, subtract the number of protons from the mass number. number of neutrons=40−19=21.
The answers would be:
In a solution, the solvent is present in a greater amount.
In a solutions, the solute dissolves in a solvent.
In general, these are the best answers. The solute is what is being dissolved and the solvent is what dissolves. A solvent comes in greater amounts in a solution and it is the dissolving agent.
For example, sugar and water.
To make a sugar water solution, you will need to dissolve sugar in water. Sugar is the solute in this case because it is what is being dissolved. The water is the solvent, because it dissolves the sugar.
If you had more sugar than water, then you cannot make a solution.
Answer:

Explanation:
k stand for equilibrium constants in terms of reaction
The higher the value of an equilibrium constant the faster the equilibrium reaction comes to completion.
Consider the example below:
⇄
where

For a faster reaction the numerator i.e. the right hand side of the equation have to be higher than the left hand side (the denominator). therefore the higher the numerator, the higher the value of the equilibrium constant and the faster the reaction get to completion thus option c is correct.
Answer:
Propane gas plus oxygen gas produces water and carbon dioxide.
Explanation:
This is the initial chemical equation: C3H8 + O2 = CO2 + H2O
This is the balanced chemical equation: C3H8 + 5 O2 = 3 CO2 + 4 H2O