The answer is B.
A cannot be the answer is melting is a physical change. No chemical reaction took place.
B is the answer as it is a EXOTHERMIC REACTION so heat will be given off.
C cannot be the answer as dissolving is basically atoms becoming ions, not a chemical reaction whereby a reactant reacts with another reactant to form a product.
D cannot be the answer. Same reason as for why A is not the answer.
Cheers.
Explanation:
The volume of a simple compressible system is not fixed. At a state of equilibrium, there should be uniformity in the entire system.
From the question we have here, these are the correct options:
1. It cannot be a mixture of different substances (e.g. oxygen and nitrogent)
2. It can be composed of any phases of a substance: solid, liquid, and/or gas
3. It's state is specified if given two independent, intensive thermodynamic properties.
rest is the state of a body which is stationary relative to a particular frame of reference or another object. When the state of a body does not changes with time with respect to its surroundings in a particular frame of reference that time it is said to be at rest.
in other words we can say that when a body has zero velocity and its position is not changing with time relative to its surrounding then it is said to be at rest.
For example a chair on which you are sitting is at rest or a table on which your desktop is kept is rest because its position is not changing.
