When the candle is burnt, the chemical energy is converted to light and heat.
Light is easily visible. Heat is dependent on the size of the candle. If a small candle is burnt heat will not be much and can only be felt if one is very close to its flame.
Sound waves and electrical energies are not created while a candle burns.
For the answer to the question above, this is the maximum displacement, the spring has only elastic potential energy. spring is constant @ 5 N/m maximum displacement = 2 cm = 0.02 m elastic potential energy = 1/2 kx² = 0.5 x 5 x 0.02² So the answer would be = 0.001 Joules