Which are the simplest pure substances that cannot be broken down into any other substances

An ideal transformer has 60 turns in its primary coil and 360 turns in its secondary coil. if the input rms voltage for the 60-turn coil is 120 v, what is the output rms voltage of the secondary coil?

Explain in physical terms how a microwave oven works. what would happen when you put a conductor in the microwave oven? explain.

When the displacement of a mass on a spring is 12a the half of the amplitude, what fraction of the mechanical energy is kinetic energy? at what displacement, as a fraction of a, is the mechanical energy half kinetic and half potential?