Two astronauts who land on the moon cannot talk with each other. What could be the reason for this ? Suggest a method for them to talk each other.

Explanation

Sound requires a medium to propagate. As there is no atmosphere (or) medium on the moon for propagation of sound, the words of one astronaut cannot be heard by another. If they have an medium for propagation of sound between them (like a toy phone), they can communicate with each other with the help of radio waves.