Answer: b. 
is positive and 
is positive.
Explanation:-
As the temperature of the pack drops, the energy has been absorbed from the pack for dissolution of 
in water. Thus as the energy has been absorbed in the reaction, the reaction is endothermic and the change in enthalpy i.e. is positive.
The entropy is the measure of degree of randomness. The entropy increases when the randomness increases and the entropy decreases when the randomness decreases. When a substance dissolves in water, it dissociate into ions and hence the randomness increases thus the change in entropy i.e. is positive.
Answer: seas
Explanation:
The ancient astronomers thought the mares on the moon were seas.
I would say D, because you need to start with nothing to measure the different sizes as they start to grow. hope this helps!
Explanation:
When we have direct sunlight, the temperature is higher compared to indirect sunlight.
Direct sunlight is usually overhead whereas indirect sunlight is at an angle to the surface.
- Direct sunlight impacts the surface with more energy concentrated on a smaller surface area.
- This warms the surface more.
- Indirect sunlight is diffuse and spreads over a wider area.
- This leads to a reduction in temperature.
