Why do lakes freeze first at the surface.

The temperature of water at the surface of deep lake is 2 °C. The temperature expected at the bottom is

A bubble of a gas released at the bottom of a lake increases to eight times its original volume when it reaches the surface. Assuming that atmospheric pressure is equivalent to the pressure exerted by a column of water 10m height, the depth of the lake is "____________" .

When a rubber sucker is pressed onto a flat glass surface, it sticks tightly on the surface. Why ? You need a large force to separate it from the surface. Why ?

Why do lanslides occur at those places only ?

Why do we see moonlight ?

Why do weeds threaten crop plants?

Why do we need filters in a power supply?

Why do we need filters in a power supply?

Why do we use iodized salt?