specific heat capacity – the amount of energy needed to increase the temperature of one kilogram of a given substance by one degree Celsius

To remember the meaning of specific heat capacity, use the following mnemonic:

To reach a specific heat, the cap (specific heat capacity) needed a certain amount of energy for each degree it rises.

Specific heat capacity is a property of a material that describes how much energy is required to raise the temperature of one kilogram of that substance by one degree Celsius (J/Kg°C). This property varies between different materials, with some substances requiring much more energy to heat up than others, which explains why different materials heat up and cool down at different rates when the same amount of energy is supplied or removed.

Water, for example, has a very high specific heat capacity of 4200 J/Kg°C, meaning it takes 4200 joules of energy to raise the temperature of one kilogram of water by one degree, which is why water heats up slowly and retains heat well. In contrast, the specific heat capacity of steel is much lower at 500 J/Kg°C meaning it heats up much more quickly and cools down much faster. 

The specific heat capacity of substance is an intrinsic property that remains constant for that material and is crucial in calculations involving energy transfer and temperature change (heating things up or cooling things down to a set temperature). For example, the formula for energy transfer is:

Energy transfer = mass x specific heat capacity x temperature change.

To work out the energy needed to heat up 0.5kg of water 20°C to 100°C.

Energy transfer = 0.5kg x 4200 J/Kg°C x 80°C = 168,000J

Energy transfer = 168,000J (168Kj)

This example shows why kettles require significant electrical energy to boil water.