Hydrosphere, atmosphere, geosphere, biosphere, anthrosphere.
Hydrosphere: Liquid, vapour or ice.
Atmosphere: Oxygen.
Geosphere: Minerals.
Biosphere: Ecosystem.
Anthrosphere: Human habitats
Answer: Ionic compounds are compounds consisting of ions.
Two-element compounds are usually ionic when one element is a metal and the other is a non-metal
Explanation: hope this helps!
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:
frequency it the measure of the wave length. The measure of the peaks and troughs is how you measure the frequency. the distance between these is the wave length.
Density = Mass ÷ Volume
D= 30g ÷ 6 cm^3
D= 5 g/dm^3
