Question: how much energy is required to raise the temperature of 1 kg of water?
Answer: Heat capacity. The specific heat capacity of water is 4,200 Joules per kilogram per degree Celsius (J/kg°C). This means that it takes 4,200 J to raise the temperature of 1 kg of water by 1°C. Lead will warm up and cool down fastest because it doesn't take much energy to change its temperature.