Answer: D. An increase in entropy
Explanation:
Entropy is the measure of randomness or disorder of a system. If a system moves from an disordered arrangement to an ordered arrangement, the entropy is said to increase and vice versa.
For a reaction to be spontaneous, the enthalpy of the solution must decrease and the entropy must increase.
To overcome a positive enthalpy of solution and allow a solid solute to dissolve in water, an increase in entropy would make the reaction spontaneous as the system would move to a more disordered state.
An index fossil is a fossil that is useful for dating and correlating the strata in which it is found.
Or it is a fossil that helps you find the date where it has been found. I rephrased that.
Answer:
The answer is: (a) positive; (b) negative.
Explanation:
The change in enthalpy (ΔH) of a reaction is the amount of energy absorbed or released during a chemical reaction carried out at constant pressure.
a) In an endothermic chemical reaction, heat energy is absorbed by the system from the surrounding. Therefore, the sign of enthalpy change for an endothermic process is positive, ΔH= positive.
b) In an exothermic chemical reaction, heat energy is released by the system into the surrounding. Therefore, the sign of enthalpy change for an exothermic process is negative, ΔH= negative.
Answer:
2. they eat plants that get their energy from the sun
Explanation:
Based on the way energy flows through an ecosystem, animals could not survive if they did not have the source of plants. So, the sun's renewable energy is important to animals because the sun helps them grow their food.
I hope this helps and makes sense!