I think it’s b
Heat isn’t transferred by sublimation
Potassium is paramagnetic meaning it is weakly attractive in a magnetic field.
Answer:
A. releases a large amount of heat
Explanation:
A reaction is said to be spontaneous if it can proceed on its own without the addition of external energy. A spontaneous reaction is not determined by the length of time, because some spontaneous reactions are completed after a long period of time. They are exothermic in nature. An example is the conversion of graphite to carbon which takes a long period of time to complete. Spontaneous reactions are known to increase entropy in a system. Entropy is the rate of disorder in a system.
In the combustion of fire, energy is released to the surroundings as there is a decrease in energy. This is an example of a spontaneous reaction because it is an exothermic reaction, which causes an increase in entropy and a decrease in energy.
Explanation:
a. The melting point is at 20C and the boiling point is at 80C. The melting point is when a solid is going through a phase change to become a liquid, that is the 1st plateau in the graph. The boiling point is when the liquid is going through vaporization to become a gas. That is the second plateau.
b. At 30C, it is a liquid, since our melting point is at 20C.
c. The substance before 20C is a solid, as we add energy, it will melt and become a liquid.
The graph is different for each substance but in this same configuration where a change in the graph is a different phase or a phase change.
Where that first incline = solid
1st plateau= melting or freezing
2nd incline= liquid
2nd plateau= vaporization or condensation
3rd incline= gas