What is the amount of energy required to raise the temperature of one kg of a substance by one °C called?

The amount of energy required to raise the temperature of one kilogram of a substance by one degree Celsius is referred to as specific heat. This property is unique to each material and indicates how much energy is necessary to change the temperature of that substance, making it a crucial concept in thermodynamics and heat transfer.

Specific heat is important in various applications, including engineering and environmental science, as it helps in calculating energy requirements for heating and cooling processes. Understanding specific heat allows engineers to design systems that effectively manage temperature changes in materials.

The other concepts mentioned, such as Charles' law and Newton's second law of motion, pertain to different scientific principles unrelated to the energy necessary for heating a substance. Similarly, latent heat of fusion specifically describes the energy required to change a substance from solid to liquid at its melting point, rather than the energy associated with a change in temperature. This highlights why specific heat is the correct answer to the question presented.