Conservation of Mass Conservation of Mass The law of conservation of mass, also known as the principle of mass/matter conservation, states that the mass of an isolated system (closed to all matter and energy) will remain constant over time. This principle is equivalent to the conservation of energy, in the sense when energy or mass is enclosed in a system and none is allowed in or out, its quantity cannot otherwise change (hence, its quantity is "conserved"). The mass of an isolated system cannot be changed as a result of processes acting inside the system. The law implies that mass can neither be created nor destroyed, although it may be rearranged in space and changed into different types of particles; and that for any chemical process in an isolated system, the mass of the reactants must equal the mass of the products. The concepts of both matter and mass conservation are widely used in many fields such as chemistry, mechanics, and fluid dynamics. Historically, the principle of mass conservation, discovered in chemical reactions by Antoine Lavoisier in the late 18th century, was of crucial importance in changing alchemy into the modern natural science of chemistry. In chemical processes, conservation of mass remains approximately true in a closed system,
Know More About :- How to Solve Linear Equations Math.Tutorvista.com
Page No. :- 1/4
Contribution of Einstein :Albert Einstein was the physicist/mathematician who vehemently and decisively put forth the relationship between mass and energy. In beginning of the twentieth century, while studying the nuclear phenomena, he observed that certain mass remains non conserved in terms of mass, however, the same remains compensated by the release of energy. In fact, many a nuclear scientists were struggling to settle the issue of non accounting of loss of mass during certain reactions. For example in a nucleus, the neutrons and similarly charged protons are held together. Actually, the protons should repel each other. Energy Definition :The concept of energy plays an important role in all sciences. In chemistry, all physical and chemical changes have energy considerations associated with them. To understand how and why energy changes happen, we need to understand energy clearly. Energy can be defined as “The ability to do work�. Since work is done whenever a force is applied over a distance, anything that can force a matter to move, or create some form of change, will have energy. Forms of Energy :Energy may appear in a variety of forms. Most commonly, energy in reactions is evolved as heat energy. Some other forms of energy are light energy, mechanical energy, sound energy, electrical energy and chemical energy. As we have seen from the chargeable batteries, energy can be easily converted from one form of energy to another. Another example which gives credence to this law is the conversion of water to steam, using heat energy.
Learn More :- Graphing Linear Inequalities Math.Tutorvista.com
Page No. :- 2/4
The steam obtained, is used to heat up many other chemical reactions, or to operate steam engines, where the energy of steam is converted into mechanical energy. Thus, all forms of energy are converted from one to another. This can be illustrated with an example. A ball, sitting in the bowler’s hand, has potential energy only. But, when the bowler tosses the ball, the potential energy of the ball gets converted to kinetic energy. (Note that the ball has obtained some energy because of the force with which the bowler is bowling). This concept can be applied to molecular level too. For example: The molecule of nitrogen also possesses potential energy, because of the chemical bond within the molecule. Energy is required to break this bond. A molecule of N2 may possess three types of Kinetic energies: translational energy, vibrational energy and rotational energy. Thus, energy is sometimes needed for a particular bond to break. Some bonds may have stored energy in them, and when they break, they release energy. If energy is required for the bond breaking processes or formation process, then the chemical reaction is said to be endothermic. But, if the stored energy is released when a bond breaks or forms, then those types of chemical reactions are said to be exothermic. The energy released from the exothermic reactions can be of any form, heat, light, sound, mechanical, etc. This energy can again be used for some other useful purpose.
Math.Tutorvista.com
Page No. :- 4/4
Thank You For Watching
Presentation