Answer
1) Radiation
2) Conduction
3) Convection
Work Step by Step
1) Since the burner is not touching anything, it is emitting energy only by emitting electromagnetic waves, so this is radiation.
2) Since the burner is heating the metal pan, which is heating the water, this is conduction.
3) Convection is when heat is transferred via motion. Since the water molecule is becoming less dense and is then rising, this is convection.
