Kinetic Theory of Matter - Essay Example

KINETIC THEORY OF MATTER This is a study that seeks to explore the concept of kinetic theory of matter, the concepts of heat and temperature and how they relate to each other. In this paper, I have also explored the relationship between heat and temperature and how they differ from one another. The Kinetic theory of matter is a theory that describes states of matter. There are three states of matter namely solids, liquids and gases. This theory states that matter is composed of particles that are in constant motion. These particles are either atoms or molecules. The particles in solids cannot move to another location but they can only vibrate because they are closely held to each other. There is enough space in liquids and therefore the particles are free to move but they attract one another. In gases there is enough free space since the particles are far apart. As more Kinetic energy is gained by the particles, the components of matter change their state; solids change into liquids and liquids change into gases. Kinetic energy is as a result of heating the particles thus making them to move apart from one another. The Kinetic theory is based on the fact that when heated, the molecules quickly vibrate and some of it moves from the matter. The physical states of matter can be explained by the kinetic theory. Heat Heat is a form of energy that is being transferred from region to another. The energy transfer is as a result of thermal contact or thermal radiation and occurs at different temperatures of the systems. Nuclear reactions such as those that are responsible for the burning of the sun release heat. Insulators can also be used to trap heat for a limited time. Energy is transferred through three modes namely conduction, convection or radiation, depending on the medium through which it is being transferred. In solids like metal, the process takes place through conduction. On the contrary some solids such as wood and plastics are poor conductors of heat. In conduction thermal energy is transferred from regions of higher temperatures to those of lower temperatures just like diffusion takes place. Convection refers to the transfer of heat energy between liquids that are in motion and a solid object. It can either be forced or free convection. In radiation, there is no contact between the objects in which the heat transfer is taking place. The transfer takes place through electro-magnetic waves, and does not require a medium. Heat is measured in joules. Temperature Temperature is the measure of the amount of heat energy in a body and the capacity for heat transfer. It can also be defined as the measurement of the mean kinetic energy of molecules in a system. The apparatus that are commonly used in the measurement of temperature are the thermometer and calorimeter. The SI unit for measuring temperature is the centigrade (Celsius), although in physics the Kelvin scale is often used. Warmth or coldness can be felt from contact with an object and this describes the object’s temperature. Relationship between heat and temperature As mentioned earlier, heat is a form of energy that is being transferred from one region to another while temperature is the measure of the amount of heat energy in a body and the capacity for heat transfer. Therefore, the amount of heat determines the temperature of a body or a region. An increase in heat energy increases the kinetic energy of molecules thus making them to move faster resulting to a rise in temperature. In addition, how fast or slow the molecules move is determined by the amount of heat energy they possess. There is a direct relationship between heat and temperature in that as the kinetic energy of molecules is increased, the temperature also increases. Differences between heat and temperatures Though the two concepts are closely related, there is a distinction between them. Temperature is the amount of inner energy of a system. On the other hand, heat is a measure of the transfer of energy from a system to another. Another difference between the two is that temperature is influenced by the amount of heat while heat itself is not affected by temperature. As the heat increases there is a rise in temperature. There is also a difference in terms of the SI units used to measure them. Heat is measured in joules while temperature is measured in degrees Celsius (°C). Properties of a substance that determine its heat capacity Heat capacity is the amount of heat needed to alter the temperature of a system by one degree. Substances have properties that determine their heat capacity. The properties include the following: Quantity A greater amount of a substance will require more heat capacity to change its temperature by one degree as compared to a small amount of the substance. For instance changing the temperature of ten thousand liters of water will require a greater heat capacity than one liter. Viscosity Less viscous substances like ethanol require less heat capacity as compared to more viscous substances such as engine oil. Size Substances with a large size require more heat capacity to alter their temperatures by one degree while substances with a small size require less heat capacity to change their temperatures.For example a rock will require more heat capacity than a small stone. Conductivity A substance which is a good conductor will allow heat energy to travel through it very fast, it will therefore require less heat capacity to change its temperature by one degree. On the contrary, poor conductors resist heat and thus requiring great amount of heat capacity to alter their temperature even by a small margin. Sources of Heat Solar Energy This is the heat derived from the sun. Heat from the sun reaches the earth form of shortwave radiation. Heat energy from the sun is used by photosynthetic plants to manufacture their own food. The sun can be termed as a natural source of energy. Earth The earth produces heat in form of geothermal energy which is derived from molten rocks and hot water present in the earth’s core. Burning Fuels Combustible substances are burnt to provide energy. Such substances include fuels such as wood, coal, kerosene, charcoal, gasoline and oil. Electricity Electricity can be converted to heat energy. For example a clothes iron generates heat from electrical energy. References Kurtus, Ron. (2011). Kinetic theory of matter. Retrieved 11 October 2011 www.school- forchampions.com/science/matter_kinetic_theory Read More