Question

how can we say that heat from sun reahes the earth by radiation and not by convection or conduction

Answer 1

Explanation:

in case of conducting object are in contact with the other object but sun is not in contact with the earth

Convection is the heat transfer due to the bulk movement of molecules within fluids such as gases and liquids, including molten rock. Convection includes sub-mechanisms of advection, and diffusion which doesn't take place between earth and the sun

Answer 2

Answer:

because above of our atmosphere there is nothing object from which heat can transferred therefore we can say that this is done by radiation .