Dating Method

If you have sample of fossil than obviously you are keen to know how old it is.  With dating method one can estimate how old an object is. Dating procedure gives you a estimated time period. The most common dating is Carbon-14 dating. Because carbon-14 has a half life of 5730 years means it will take 5730 years to decay half of it original quantity. So if you have 10 g of Carbon-14 now than after 5730 years 5 g of Carbon-14 will decay and will form different element and you will left with 5 g. So what is the equation that uses to determine the age. There are two different equation of dating but in this post I will discussing about the first equation which is: 

                                                                     N = N₀ e^ˉλt

N is remaining, N0 is original quantity e is approximately 2.718 and t stands for the age and lambda λ

Lets do an example: 

You have a sample of a fossil, originally it has 0.0025 g of C-14 and now you has 0.00068 g. How old this fossil is ? 

ln is the natural log and t stands for the half life of the radioactive isotope in this case C-14. 

So the sample that we had it is approximately 10762 years old. Though it is not exactly this many years, we should have use other radioactive isotope that has a half life of 9000 - 15000. So before doing the dating archaeologist needs predict how old the fossil might be. If you have any question regarding the calculation than comment below I will try to solve this. Note that this blogs is designed to high school students, so if you find something ambiguous or wrong so please don't hesitate to comment.  

Calculate Mass Defect Cont'd

This post will focus in finding mass defect and binding energy of a reaction. In the last post, I did not mention about binding energy. Here, we will learn how to calculate binding energy as well. Lets find mass defect and binding energy for following equation: 

                                             

Mass of Ne-21= 20.99 u Mass of He-4 = 4.002 u  Mass of Mg-24 = 23.98 and Mass of n= 1.008

Then, Mass defect = (mass of Ne + Mass of He) - (Mass of Mg + Mass of n)

                              = (20.99 u + 4.002 u) - (23.98 u + 1.008 u)

                              =  24.992 u - 24.988 u

                              = 0.004 u

There are two unit to calculate binding energy one in MeV and second one is in J. In this we will calculate in MeV because it is the SI unit for binding energy and fastest plus easiest way to calculate. 

Binding Energy = Mass defect × 931.49 MeV/u 

                          = 0.004 u × 931.49 MeV/u

                          = 3.726 MeV

Note: 1 u = 931.49 MeV

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Calculate Mass Defect

Mass Defects is the difference between masses of isotopes and its masses number. 

Lets calculate the mass defects of tritium, H-3 which has a mass of 3.016049 u. 

It requires 2 neutrons and one proton. 

Mass of one proton               = 1.007825 u

Mass of two neutron             = 2(1.008665) u

Sum of proton and neutron   = 3.025155 u

So the mass defect = 3.016649 u − 3.02515 u = −0.009106 u

Note: the singe plus or minus doesn't matter it just tells this mass has been lost. 

Nuclear Power Plant

This post will briefly describe how Nuclear Power Plant works. Nuclear Power Plants is know as thermal power station because it heats the water to get electricity.

In a nuclear power plant you have reactor or fuel rods immersed in water than you have control rods a pump steam generator and turbine areas. Once the chain reaction starts in this case Uranium-235 it decays to Krypton-89, Barium-144 and 3 neutrons. Through this it releases heat energy, because of high pressure the water does not boils. In this case a pump that helps to exchange the water and water are supplied into another that helps to create steam. Steam than passes through a pipe line to rotate than turbine. Thus, the rotation of turbine generates electricity. Nuclear process is the most efficient method to generate electricity if the reaction held control. Once the expected amount of heat released by the reaction control rods are immersed into the water. These rods are made of Cadmium metal which can easily absorb water. These rods absorbs neutrons for further reactions. 

Nuclear Fission & Reactor

Nuclear Fission

The nuclear fission reaction refers to a reaction that splits of nucleus into two or more fragments. The every splits releases energy that could use in many different ways.  Fission reaction occurs when a nucleus divided into two or more fragments, releasing neutrons and energy. The uranium isotope, U-235, undergoes fission reaction when it bombarded with a neutrons. The element barium and Krypton are the result of the reaction. In fission on or more of the neutrons causes the fission, that fission releases three more neutrons, each one neutron causes more fission. This continual process of fission reaction called a chain reaction. 

Nuclear Reactor

Once the fission reaction started if continues until the reaction has finished. In this reaction it releases alpha, beta or gamma rays. In our time the fission reaction are used to generate electricity. A power station are built near to a river where large body of water available.  A nuclear power station is divided into many different sector. In one sector fuel road or reactor are immersed into water. Once the reaction starts it produces heat energy that boils the water and the steam than goes through a pipe and hits turbines to spine. As turbines starts to rotate it generates electricity. In the mean time when chain reaction starts its needs to be control otherwise it will burn everything and the radiation will free to move in the atmosphere. To stop the reaction control rods immersed in water. This rods are made of cadmium metal that can easily absorb neutrons. When they inserted into the reactor, they absorb enough of neutrons releases by the fission reaction to prevent further chain reaction.