plz answer these questions


1# Why water boils quicker on mountains?
2# Why rainbow is produced in the sky after rainfall and sunlight?
3# Why water remains cool in Earthenware pitcher?
4# Why milk is considered as an ideal food?
5# Why meat takes longer to cook on the mountains?
6# Why ica and salt mixture is used as a freezing agent in manual ice-cream maker?
7# Why greenhouse operators paint their glass roof white in summer?