Explanation :
As we know that the Gibbs free energy is not only function of temperature and pressure but also amount of each substance in the system.
where,
is the amount of component 1 and 2 in the system.
Partial molar Gibbs free energy : The partial derivative of Gibbs free energy with respect to amount of component (i) of a mixture when other variable 
are kept constant are known as partial molar Gibbs free energy of 
component.
For a substance in a mixture, the chemical potential 
is defined as the partial molar Gibbs free energy.
The expression will be:
where,
T = temperature
P = pressure
is the amount of component 'i' and 'j' in the system.
Answer: D. Made of only one kind of atom
Explanation:A compound forms whenever two or more atoms form chemical bonds with each other.
Explanation:
1)observation is that the light doesn't reach some parts of the points of interest
2)this is because the rays of the light were interrupted by different objects thus making the light divert different ways.
