Kinetic theory of matter tries to explain all molecules in terms of motion. The theory posits that every substance consists of many small particles referred to as molecules. Substances in this case are called matter and are in three forms; solids, liquids, and gases. Solids have molecules that are closer to each other by intermolecular forces. Liquids on the other hand have molecules slightly far apart with gases the furthest apart. Furthermore, according to this theory all the molecules are in constant random motion referred to as Brownian motion (Chang, 2004).
The study of heat relates to kinetic theory of matter as it is analyzed through the molecules of matter. Since molecules in matter are in constant vibration according to the theory, it is noted that heat increases motion. The intermolecular forces are loosened when molecules are heated and hence result in changes of state. In addition, the constant vibration of molecules result in collisions if the matter is enclosed resulting to pressure.
Therefore, heat is the thermal interactions of molecules that result in transfer of energy amongst each other. Transfer of energy flows from a place of higher concentration to those of lower ones meaning that heat flows from systems having higher temperatures to those with low temperatures. Therefore, if two or more molecules or systems have the same temperatures, then there would be no flow of energy. In this regard heat can be quantified and analyzed since it is a form of the many types of energy. The unit of measuring heat is the Joule and can be conserved according to the first law of thermodynamics. This conservation aspect makes it impossible to destroy heat hence the reason why it can be transformed to another form such as kinetic energy or transferred to another system.
In transferring heat between systems, there are three mechanisms. They are conduction, convection, and radiation. In conduction, heat transfer is felt between solids. In this mechanism there is a temperature gradient in a ponderable matter (can be solid, liquid, or gases) resulting in transfer without external forces until thermal equilibrium is achieved (Shipman, Wilson, & Todd, 2012). Convection heat transfer is where heat is transferred by large scale motion of currents in fluids. Fluids in this case are liquids and gases. Radiation heat transfer is where heat transfers by electromagnetic radiation since all matter that have temperatures above absolute zero emit radiation.
Temperature on the other hand is a physical feeling defining the hotness and coldness of an object. In coldness, the object is identifies as having low temperature while those classified as hot have hot temperatures. The motion of molecules in matter is directly proportional to its temperature. Hence the definition by Shipman et al. (2012, p. 122), is that “temperature is the derivative of internal energy with respect to entropy.” Temperature has a role in influencing chemical reaction; the rate and extent. This is the reason why human bodies have complex systems and mechanisms that maintain temperatures at 37.50C. A degree below or above the normal mark results in negative health ramifications.
Temperature is measured using a thermometer with units such as Celsius, Fahrenheit, and the Kelvin. The most common unit is the Celsius that has its lowest point being zero and the highest 100. The zero mark is the scale where water freezes and equivalent to 273.15K in the Kelvin scale. The -273.150C scale is similar to the 0K and refers to the absence of internal energy in a body.
Heat and temperature are different where the former is the quantity of energy in a system with SI unit being the Joule. Heat can also be transferred from one area to another through mechanisms of radiation, conduction, or convection. Heat is also related to kinetic energy where faster motions in molecules result in higher heat while slower ones having less heat.
Temperature on the other hand is the mean molecular motion (Kinetic energy) inside a body represented by units such as Celsius, Fahrenheit, and Kelvin. In some situations, temperature unlike energy is that temperature does not change when heat is being transferred. For instance, temperature of water remaining constant as it boils even as more energy is put into the water. However, the general assumption is that heat increases as temperature rises ignoring latent heat of fusion and vaporization.
The heat capacity is defined as the amount of heat required to change the temperature of a substance. The amount of matter a substance contains is a factor that determines heat capacity. Matter in this case is measured in terms of mole, volume, or mass. Therefore, increasing the amount of matter will increase the heat capacity since they are directly proportional. The degree of freedom is also a property where the number of degrees of freedom available in a substance enables it to store heat. One such degree of freedom is kinetic energy signified as temperature. Therefore, the larger the degree of freedom, the more the heat capacity. Quantum effects is also a property affecting heat capacity where the effects limit the degrees of freedom from storing heat energy at full potential (Chang, 2004).
In conclusion, heat is a form of energy and occurs when an object transfers thermal energy to a body that does not have, or has less of thermal energy. The sources are many and can be listed as:
Burning Fuels: Fuels such as wood, petroleum, and charcoal burn and result in heat energy.
Chang, H. (2004). Inventing Temperature: measurement and scientific progress. Oxford: Oxford University Press. Pp. 167-198
Shipman, J., Wilson, J.D., & Todd, A. (2012). An introduction to physical science. Ohio: Cengage Learning. Pp. 121-167