Conservation Of Matter And Energy

Conservation of matter and energy

Introduction to conservation of matter and energy
The conservation of matter and energy means that the total amount of energy and the total amount of matter is always constant in a given closed, isolated system. In other words, neither energy nor mass can be created or destroyed in any physical or chemical process.
Formation of the law of conservation of matter and energy

Until the discovery of mass - energy equivalence by Albert Einstein in 1905, conservation of matter and conservation of energy were two different conservation laws. Conservation of matter implied that matter can neither be created nor destroyed, and conservation of energy implied that energy can neither be created nor destroyed. The two were not related to each other in any aspect except that they were both conservations laws.
But, as physics and science increased its parameters with the advance of technology,nuclear reactions were discovered, and it was discovered that in nuclear fusion and fission reactions, the total mass of reactants does not equal to the total mass of the products obtained. For example, in the following nuclear fusion reaction,
There is a difference between the mass of the reactants, that is, four atoms of Hydrogen, and the mass of the products, that is, one atom of Helium. This difference can be clearly depicted by the following diagram.
Diagram representing the differnce in masses of equivalent amounts of Hydrogen and Helium
The difference in the mass could not be explained by any laws, and furthermore, it was a direct failure of the law ofconservation of mass. Huge amount of energy was produced in the above reaction, and this "creation" of energy and in was certainly a setback to the law ofconservation of energy. But in 1905, Albert Einstein pointed out that in the chemical reactions like above, the difference in mass of the reactants and products is balanced by the release of energy, that is, some mass of the reactants was converted into energy, and since matter and energy are the same thing, conversion of matter into energy cannot be regarded as the creation of energy. He also gave the formula to calculate the amount of energy produced as follows:-
`e = mc^2` .
Conservation of Matter and Energy : Albert Einstein

Albert Einstein pointed out that matter and energy are the same thing, and matter can be converted to energy. Thus, if energy is being "produced" in a nuclear reaction, although the total calculated amount of energy is increasing, but since the calculated amount of mass is decreasing, and matter and energy are the same thing, therefore the total energy of the system can be regarded as constant.
Thus, the law of conservation of energy and the law of conservation of matter were combined, to form the law of conservation of matter and energy. Note that the term "Law of conservation of energy" implies the law of conservation of matter and energy.

Energy is usually defined as the ability to do work. This is an anthropocentric and utilitarian perspective of energy; however, it is a useful definition for engineering where the aim of machines is to convert energy to work. As a more general description, we would say that energy is a fundamental entity whose availability and flow are required for all phenomena, natural or artificial.
An understanding of how energy is generated and measured is central to our decisions concerning the use and conservation of energy. Large-scale production of energy evolved over centuries but grew radically in the last 400 years and especially since the Industrial Revolution. A century of development and commercialization of electric power technology has ensured an easy supply, and continuous measurement.
Energy is derived in usable forms from numerous sources, such as flowing water, fossil fuels (e.g., coal and natural gas), uranium, and the sun. Electricity is a widely used form of energy. Any of these sources can be used to generate electricity. Liquid fuels such as gasoline and diesel derived from fossil fuels are a widely used source of energy. These fuels form the basis of our easy transportation. A complete understanding of the complexities of the energy systems within the natural environment requires knowledge of some basic physics and chemistry. This is discussed later in this unit in the sections under "Science Notes."

Conservation of energy

In physics, the law of conservation of energy states that the total energy of an isolated system cannot change—it is said to be conserved over time. Energy can be neither created nor destroyed, but can change form, for instance chemical energy can be converted to kinetic energy in the explosion of a stick of dynamite.
A consequence of the law of conservation of energy is that a perpetual motion machine of the first kind cannot exist. That is to say, no system without an external energy supply can deliver an unlimited amount of energy to its surroundings.[2]
Conservation of Matter and Energy
Its known that matter is anything that has mass and occupies space. When somebody says that matter can neither created nor be destroyed That contradicts our every day experience where we see a tree burns, a chalk gets powered into particles and many. Here you can justify by saying that total no of particles before the action is equal to total no of particles after the reaction.Energy is the capacity to do work on any physical system. When considering the types of energy we come across various types of energy like chemical energy, kinetic energy, heat energy, light energy etc.It also tells the same thing about energy that it can neither be created nor be destroyed but can only be transferred.

Thus it can be in general stated that:Matter and energy can neither be created nor be destroyed but can only converted or transformed into another form. Thus it can be said that total amount of mass and energy is constant.

Law of Conservation of Matter and Energy

Here are some examples on conservation of matter and energy:
When a chemical energy gets converted to kinetic energy, the kinetic energy gets converted into mechanical energy and so on. Hence there will be transfer of energy. Lets see some such kind of illustrations of conservation of energy:
1. Water falls from the sky that converts the potential energy to kinetic energy. This energy is then used to rotate the turbine of a generator to produce electricity. In this process the potential energy of water in a dam can be turned into kinetic energy which can then become electric energy.
2. When a boy kicks a football the potential energy stored in the boy is converted into kinetic energy setting the boy into motion.
Lets see some illustrations on conservation of matter:
1. When we light the wood it burns down into ash.
2. The iron get converted into rusted particles when exposed to moisture.
Thus matter like wood, iron etc gets converted into carbon dioxide, water vapor and ash. Hence matter transforms from one form to another. When an object of mass is molten the system does not change that result into an another object of same mass.