Question

how do astronauts talk to one another on moon

Answer 1

The astronauts have devices in their helmets which transfer the sound waves from their voices into radio waves and transmit it to the ground (or other astronauts in space). This is exactly the same as how your radio at home works.

Answer 2

THE ASTRONAUTS HAVE THEIR SPECIAL DIVICES OR HELMETS WHICH TRANSFER THE SOUND FROM ONE TO ANOTHER