Answer:
When 
and 
Explanation:
The spontaneity of a reaction can be determined by the sign of the Gibbs free energy change. For a spontaneous reaction, the change in Gibbs free energy should be negative, meaning:
Since the temperature value here corresponds to the absolute temperature, this implies that T > 0 for any T. Therefore, to have a negative difference for any temperature value, the first term, the change in enthalpy, should be negative and the change in entropy should be positive, so that we always subtract a positive number from a negative number. This corresponds to a negative value in 
.
Answer:
a chemical change is a change that changes the substance into a whole new substance.
Examples include: burning wood, a banana peel rotting, milk souring, and even your food/drinks digesting.
Answer:
C rusting iron
Explanation:
water evaporating and melting is an example of physical change it doesn't change the H2O composition of the atoms, rubbing water on paper doesn't change any atoms or molecules. so the only answer that leaves is rusting iron because when an iron nail comes into contact with water and is then exposed to the air, it rusts, forming a brown-red substance. This process changes the chemical composition of the original substance.
