ALBERT EINSTEIN AT SCHOOL

First time when I read the the title of this story , I thought that this story would be very interesting. Yes story is interesting. Albert was honest and truthful as he confessed to his history teacher that he don't see a point in learning dates. But instead of trying to understand him , he scolded him. I did not like this part of the story. This story tells us that for all our scientist's school life might be very difficult for them. I think they faced a lot of difficulties in their life. Yet they didn't loose hope and today  we can see the result. So this story encouraged me to achieve my destiny whether people support me or not. Einstein was also alone but there were some people like Yuri,  Elsa, Dr Ernest and Mr Koch who understood him and supported him. So, this is a fine story and encourages us a lot.   

RANGA'S MARRIAGE

This story fascinated me a lot. I like the character of the narrator. He used his brain and was able to change the decision of  Ranga . Ranga confessed that he like Ratna. He became ready to marry her. The way the narrator changed the mind of Ranga about marriage is very interesting. I think that a film should be made on this story. But Ratna marry Ranga when she was not matured and was not literate. So I did not like this part of the story. Otherwise the overall story is very dramatic and humorous. The last scene is very lovely. Ranga and Ratna lived happily. What a happy ending!   

INVESTIGATORY PROJECT

CHEMISTRY

THERMODYNAMICS



Thermodynamics is a branch of physics concerned with heat and temperature and their relation to energy and work. It defines macroscopic variables, such as internal energy, entropy, and pressure, that partly describe a body of matter or radiation. It states that the behavior of those variables is subject to general constraints, that are common to all materials, not the peculiar properties of particular materials. These general constraints are expressed in the four laws of thermodynamics. Thermodynamics describes the bulk behavior of the body, not the microscopic behaviors of the very large numbers of its microscopic constituents, such as molecules. Its laws are explained by statistical mechanics, in terms of the microscopic constituents

LAWS OF THERMODYNAMICS

Zeroth law of thermodynamics: If two systems are in thermal equilibrium respectively with a third system, they must be in thermal equilibrium with each other. This law helps define the notion of temperature.

First law of thermodynamics: When energy passes, as work, as heat, or with matter, into or out from a system, its internal energy changes in accord with the law of conservation of energy. Equivalently, perpetual motion machines of the first kind are impossible.

Second law of thermodynamics: In a natural thermodynamic process, the sum of the entropies of the participating thermodynamic systems increases. Equivalently, perpetual motion machines of the second kind are impossible.

Third law of thermodynamics: The entropy of a system approaches a constant value as the temperature approaches absolute zero.^[2] With the exception of glasses the entropy of a system at absolute zero is typically close to zero, and is equal to the log of the multiplicity of the quantum ground state.

INTERNAL ENERGY



One of the thermodynamic properties of a system is its internal energy, E, which is the sum of the kinetic and potential energies of the particles that form the system. The internal energy of a system can be understood by examining the simplest possible system: an ideal gas. Because the particles in an ideal gas do not interact, this system has no potential energy. The internal energy of an ideal gas is therefore the sum of the kinetic energies of the particles in the gas.

The kinetic molecular theory assumes that the temperature of a gas is directly proportional to the average kinetic energy of its particles, as shown in the figure below.

 

The internal energy of an ideal gas is therefore directly proportional to the temperature of the gas.

E_sys = ³/₂ RT

In this equation, R is the ideal gas constant in joules per mole kelvin (J/mol-K) and T is the temperature in kelvin.

The internal energy of systems that are more complex than an ideal gas can't be measured directly. But the internal energy of the system is still proportional to its temperature. We can therefore monitor changes in the internal energy of a system by watching what happens to the temperature of the system. Whenever the temperature of the system increases we can conclude that the internal energy of the system has also increased.

THE SYSTEM AND THE WORK



The system is usually defined as the chemical reaction and the boundary is the container in which the reaction is run. In the course of the reaction, heat is either given off or absorbed by the system. Furthermore, the system either does work on it surroundings or has work done on it by its surroundings. Either of these interactions can affect the internal energy of the system.

E_sys = q + w



Two kinds of work are normally associated with a chemical reaction: electrical work and work of expansion. Chemical reactions can do work on their surroundings by driving an electric current through an external wire. Reactions also do work on their surroundings when the volume of the system expands during the course of the reaction The amount of work of expansion done by the reaction is equal to the product of the pressure against which the system expands times the change in the volume of the system.

w = - PV

The sign convention for this equation reflects the fact that the internal energy of the system decreases when the system does work on its surroundings.

HEAT AND THERMAL ENERGY

When scientists originally studied thermodynamics, they were really studying heat and thermal energy. Heat can do anything: move from one area to another, get atoms excited, and even increase energy. Did we say energy? That's what heat is. When you increase the heat in a system, you are really increasing the amount of energy in the system. Now that you understand that fact, you can see that the study of thermodynamics is the study of the amount of energy moving in and out of systems.

ENERGY AND ENTROPY

 Another big idea in thermodynamics is the concept of energy that changes the freedom of molecules. For example, when you change the state of a system (solid, liquid, gas), the atoms and/or molecules have different arrangements and degrees of freedom to move. That increase in freedom is called entropy. Atoms are able to move around more and there is more activity. That increase in freedom (also called randomness) is an increase in entropy.

CHEMICAL THERMODYNAMICS

Thermodynamics is defined as the branch of science that deals with the relationship between heat and other forms of energy, such as work. It is frequently summarized as three laws that describe restrictions on how different forms of energy can be interconverted. Chemical thermodynamics is the portion of thermodynamics that pertains to chemical reactions.

ENTHALPY Vs INTERNAL ENERGY



What would happen if we created a set of conditions under which no work is done by the system on its surroundings, or vice versa, during a chemical reaction? Under these conditions, the heat given off or absorbed by the reaction would be equal to the change in the internal energy of the system.

E_sys = q (if and only if w = 0)

The easiest way to achieve these conditions is to run the reaction at constant volume, where no work of expansion is possible. At constant volume, the heat given off or absorbed by the reaction is equal to the change in the internal energy that occurs during the reaction.

E_sys = q_v (at constant volume)

The figure below shows a calorimeter in which reactions can be run at constant volume. Most reactions, however, are run in open flasks and beakers. When this is done, the volume of the system is not constant because gas can either enter or leave the container during the reaction. The system is at constant pressure, however, because the total pressure inside the container is always equal to atmospheric pressure.

If a gas is driven out of the flask during the reaction, the system does work on its surroundings. If the reaction pulls a gas into the flask, the surroundings do work on the system. We can still measure the amount of heat given off or absorbed during the reaction, but it is no longer equal to the change in the internal energy of the system, because some of the heat has been converted into work.

E_sys = q + w

We can get around this problem by introducing the concept of enthalpy (H), which is the sum of the internal energy of the system plus the product of the pressure of the gas in the system times the volume of the system.

H_sys = E_sys + PV



The change in the enthalpy of the system during a chemical reaction is equal to the change in its internal energy plus the change in the product of the pressure times the volume of the system.

H = E + (PV)

Because the reaction is run at constant pressure, the change in the enthalpy that occurs during the reaction is equal to the change in the internal energy of the system plus the product of the constant pressure times the change in the volume of the system.

H = E + PV (at constant pressure)



Substituting the first law of thermodynamics into this equation gives the following result.

H = (q_p + w) + PV

Assuming that the only work done by the reaction is work of expansion gives an equation in which the PV terms cancel.

H = (q_p - PV) + PV

Thus, the heat given off or absorbed during a chemical reaction at constant pressure is equal to the change in the enthalpy of the system.

H = q_p (at constant pressure)

The zeroth law of thermodynamics involves some simple definitions of thermodynamic equilibrium. Thermodynamic equilibrium leads to the large scale definition of temperature, as opposed to the small scale definition related to the kinetic energy of the molecules. The first law of thermodynamics relates the various forms of kinetic and potential energy in a system to the work which a system can perform and to the transfer of heat. This law is sometimes taken as the definition of internal energy, and introduces an additional state variable, enthalpy. The first law of thermodynamics allows for many possible states of a system to exist. But experience indicates that only certain states occur. This leads to the second law of thermodynamics and the definition of another state variable called entropy. The second law stipulates that the total entropy of a system plus its environment can not decrease; it can remain constant for a reversible process but must always increase for an irreversible process.



HEAT OF ATOMS



Now all of this energy is moving around the world. You need to remember that it all happens on a really small scale. Energy that is transferred is at an atomic level. Atoms and molecules are transmitting these tiny amounts of energy. When heat moves from one area to another, it's because millions of atoms and molecules are working together. Those millions of pieces become the energy flow throughout the entire planet.          HEAT AND THERMAL MOVEMENT 



Heat moves from one system to another because of differences in the temperatures of the systems. If you have two identical systems with equal temperatures, there will be no flow of energy. When you have two systems with different temperatures, the energy will start to flow. Air mass of high pressure forces large numbers of molecules into areas of low pressure. Areas of high temperature give off energy to areas with lower temperature. There is a constant flow of energy throughout the universe. Heat is only one type of that energy.

The Address

Its a good and inspiring story of a daughter...
I like the way the story is written...
It is based on a good theme....
I too suggest you to read it....
You'll too like it.....