From which energy store is energy transferred when fossil fuels are burnt?

When fossil fuels are burnt, energy is transferred from the chemical energy store. Fossil fuels, such as coal, oil, and natural gas, contain stored energy in the bonds between atoms in their molecules. When combustion occurs, the chemical bonds are broken, releasing this stored energy primarily in the form of heat and light. This process transforms the chemical energy into thermal energy, which can then be used to produce steam, generate electricity, or provide heat.

Other energy stores listed, such as nuclear, kinetic, and gravitational, are not relevant to the process of burning fossil fuels. Nuclear energy pertains to the energy stored within the nucleus of atoms, kinetic energy relates to motion, and gravitational energy involves the potential energy held by an object due to its position in a gravitational field. Only chemical energy is involved in the combustion of fossil fuels.