About discovery of 115 element

Even though nearly 80 years have passed since the discovery ofTechnetium, the first “synthetic” element, the periodic table of elements remains a work in progress.

On Tuesday, evidence for the existence of element 115 — a potential new addition to the periodic table - was published in The Physical Review Letters.

The element has 115 protons, only lives for fractions of a second on average, and is one of several that may eventually be considered for entry into the exclusive chemical club.

To see what it takes to add a new element to the periodic table (below) — and to understand why seeking to make these new elements is important — we first need to understand what scientists are trying to create.

An island of stability

Element 115 is a “superheavy” element — only one of a cluster of synthetic elements with atomic numbers greater than 104. Including all the isotopes of each superheavy element, this cluster forms an “island of stability” at the very top end of thenuclear chart.

As the name suggests, the occupants of this island are heavy, weighing around 20% more than the largest naturally occurring element, Uranium. But they are also special in another way: they only exist because of a rather important quantum mechanical feature of the subatomic world.

In this world, some numbers of protons and neutrons are special — so special, in fact, that they’re called “magic numbers”. Nuclei with magic numbers of protons or neutrons (or sometimes both) are more stable than their neighbours, meaning that they live longer on average than the nuclei that surround them on thenuclear chart.

At the centre of the island of stability, two magic numbers intersect. These magic numbers make the quest for superheavy elements possible.

Smash and crash

Creating new elements is not a simple process. Scientists use a particle accelerator to smash light atoms into a thin metallic foil that contains heavier atoms, in the hope that the two nuclei at the centre of these atoms will come together, or fuse, forming a heavier element. This sounds like a rather brutal process, and it is, except for one thing: atoms are mostly empty space.

A view into the 120m-long linear accelerator at GSI, which accelerated the calcium ions used to produce element 115.

If an atom were blown up to the size of the Melbourne Cricket Ground, the atomic nucleus at its centre would be the size of a small grape. To create a new element, the tiny nuclei at the centre of both atoms must be close enough to touch. Only then can the nuclear force — the strong force that glues the protons and neutrons in the atomic nucleus together — begin to act.

There are two things working against us:

1. Atomic nuclei are positively charged. Like charges repel each other, so the accelerated nucleus has to have enough energy to overcome this repulsive force, but not so much energy that the two colliding nuclei will quickly tear themselves apart again.
2. Even if the nuclei are close enough to touch, the chance that those two nuclei properly fuse into a new element is very small — so small, in fact, that we may only have one or two superheavy elements to show for several weeks of continuous effort.

The rest of the time, the atomic collisions result in many other outcomes, such as other elements, all of which have to be separated somehow from the elements we are interested in creating.

A drop in the sea

For the latest work on element 115, a powerful device called TransActinide Separator and Chemistry Apparatus (TASCA) was used to roughly separate out the element of interest (along with other products with similar mass and charge) from the rest of the products of the atomic collision. TASCA is a gas-filled separator — one of several used for superheavy and heavy element studies in the world — that exploits the fact that particles with different masses and charges take separate paths through a magnetic field.

The TASCA at GSI Darmstadt is a highly efficient device for studying superheavy elements.

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But a gas-filled separator is not enough to uniquely separate out and identify a new element. Other ways of detecting and identifying the presence of a new superheavy element must be used, in order to make a strong case that the element does indeed exist.

Here is where the problem gets tricky. How do you identify a short-lived element you know nothing about, particularly when you only have an atom at a time to work with?

For the case of superheavy elements, there is no single perfect answer to this question. Scientists typically use a wide range of clues to identify the elements created. Some of these clues originate from the atomic properties of the element — in other words, from the electron cloud surrounding the atomic nucleus. Others originate from the atomic nucleus, and may be different for different isotopes of a given element.

To identify new superheavy elements, scientists often begin by looking for characteristic decay patterns that lead us back to familiar territory — in other words, nuclei we already know a lot about. Because superheavy nuclei are not very stable, they tend to decay after a short period of time by emitting an alpha particle, or helium nucleus.

Alpha decay. Wikimedia Commons

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After each alpha decay, a new nucleus — lighter than its parent by two protons and two neutrons — is created. This new nucleus may also decay by emitting another alpha particle, and so on, until one of the daughter nuclei in the chain simply breaks into two by a process known as spontaneous fission.

Throughout this process, each atom may also emit other types of radiation resulting from the intricate factors influencing how each atomic nucleus decays. With the right detectors in place, all of these additional radiation signatures can be used to make a case for the existence of a new element.

Joining the club

The discovery of a new element, then, is often indirect. This is why new elements often have to wait a long time before they are officially added to the periodic table.

To be added to the periodic table, an independent committee of scientists from the international unions of Pure and Applied Chemistry (IUPAC) and Physics (IUPAP) carefully weigh all evidence supporting each element’s existence and decide whether that evidence is strong enough to warrant a new entry in the periodic table. In most cases, elements that have been detected independently at more than one laboratory, ideally through more than one method, have a reasonable chance of making it into the table.

For element 115, a joint Russian-US collaboration first discovered signs of the element’s existence at the Joint Institute for Nuclear Research (JINR) in Russia in 2004.

The more recent work, which was conducted at the GSIHelmholtz Centre for Heavy Ion Research in Germany, will play an important role in strengthening the element’s case. Crucially, the new findings reveal both atomic and nuclear signatures that strongly support the element’s existence.

Work in the radiation chamber of TASCA. Gaby Otto/GSI

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A case for big science

At this point, you may be asking this: why create these new elements? The experiments are incredibly difficult, and even though new elements are discovered, they only live for a short time and have no immediate, obvious use.

The most direct answer is it is predicted that some of these as yet undiscovered superheavy elements will live longer than their current counterparts, and may even have applications that we have not yet dreamt of.

But the benefit of big science like this goes beyond direct impacts. By continuously reaching towards the edge of our knowledge, we often have to completely change how we think.

And there is something more difficult to define, too: the sense of collective wonder plainly reflected in the headlines announcing each new element. The fact that science has not yet completed something so iconic, so seemingly permanent, as the periodic table of elements is enough to remind all of us that we still have a great deal to learn about our universe.

Making of super heavy elements

The Russian lab’s recipe for making new superheavy elements begins with expensive ingredients: rare, heavy isotopes of calcium and of an existing heavy element like plutonium. When the two kinds of atoms collide at high speed, they sometimes fuse into a new superheavy one. Here are six key steps.

   1. BAKE a solid calcium compound at 1,300 degrees Fahrenheit in an oven (shown here with its clamshell cover off). The calcium vaporizes, forming a gas that can be shaped into a high-energy beam.

·             2. IONIZE the calcium atoms by stripping off some of their electrons in a kind of microwave oven (red cylinder). The positively charged ions can now be accelerated by electric and magnetic fields.

      3. ACCELERATE the ions in a pie-shaped cyclotron. Here you’re at the center, where the ions come in. The dark wedge of an electrode assembly, five feet wide, is pointing at you from the mouth of a copper-clad pipe, which generates a strong electric field. Under its sway, the calcium ions spiral out through the hollow electrodes

      4. EXTRACT the calcium ions from the outer rim of the cyclotron, and use magnets to channel them down this tube in a four-inch-wide beam. They’re traveling at 67 million miles an hour, or a tenth the speed of light.

      

       5.SMASH the calcium ions into a spinning target. It’s the crinkly foil barely visible just inside the rim of the brass wheel. The foil is coated with plutonium or another heavy element—which one depends on what new element is being cooked.

       

      6.DETECT the new element. It’s the needle in the haystack of debris coming out the back of the foil target. The first step at Dubna is to catch all that in a disk of red-hot graphite, slowing it down for analysis.

Creation of 115 element

A calcium-48 ion is accelerated to a high velocity in a cyclotron and directed at an americium-243 target. The accelerated calcium-48 ion collides into an americium-243 target atom (above) and creates the new 115 element that begins decaying with the emission of alpha particle into element 113.

About Superheavy Elements

What is a heavy element?What is a superheavy element?What is an atomic number?
How are new elements discovered?
What is a cyclotron?
What are some properties of artificially made elements?
What is the "island of stability"?
What is the "sea of instability"?
Why is discovering new superheavy elements important?
How can superheavy elements be used?
How long did it take to discover elements 113 and 115?
Why are the superheavy-element experiments conducted in Russia?
What special equipment is needed to discover superheavy elements?
When will elements 113 and 115 be named?
1. What is a heavy element?
A heavy element is an element with an atomic number greater than 92. The first heavy element is neptunium (Np), which has an atomic number of 93. Some heavy elements are produced in reactors, and some are produced artificially in cyclotron experiments.
2. What is a superheavy element?
The definition of superheavy elements (SHE) varies among different groups of people. We use the term term SHE to refer to those elements with an atomic number greater than or equal to 112. The first superheavy element is element 113, which has been recently discovered by a collaboration of scientists from the Lawrence Livermore National Laboratory and the Joint Institute of Nuclear Research in Russia. Like some of the heavy elements, superheavy elements are produced artificially in cyclotron experiments.
3. What is an atomic number?
The atomic number refers to the number of protons in an element’s nucleus. Each element has a unique atomic number and is known by that number until it receives an official name. For example, the two new superheavy elements 113 and 115 have 113 and 115 protons, respectively, in their nuclei.
4. What are isotopes?
Elements are defined by their atomic numbers or number of protons in the nucleus. Elements, however, have more than one isotope. An isotope contains varying numbers of neutrons in the nucleus. Gold, for example, has one stable isotope often denoted as . It has an atomic number of 79 (meaning 79 protons in the nucleus) and a mass number of 197, or the total number of neutrons and protons in the nucleus. Thus, there are 197 – 79 = 118 neutrons in this isotope. However, more than 30 isotopes of gold are known. Each isotope has its own decay characteristics and half-life. For example, , an isotope with one more neutron (119) that the stable isotope , has a half-life of 2.7 days and decays by beta-decay. A very different gold isotope,  , has a half-life of 5 ms and decays by alpha-decay.
5. How are new elements discovered?
Several experimental techniques have been used to make new chemical elements. Some of these include heavy ion transfer reactions, cold or hot fusion evaporation reactions, neutron capture reactions, light-ion charged particle induced reactions, and even nuclear explosions. These techniques each have advantages and disadvantages making them suitable for studying nuclei in certain regions.
The types of nuclear reactions that have been successfully used to produce new elements in the last decade are cold fusion reactions and hot fusion reactions. Cold fusion reactions use beam and target nuclei that are closer to each other in mass in order to produce a compound nucleus (the complete fusion of one target nucleus with one beam nucleus) with generally lower excitation energy that typically requires evaporation of one or no neutrons. This generates fewer neutron-rich isotopes of an element that have higher survival probabilities with respect to fission, but have lower fusion probabilities. An example of this type of reaction is ⁷⁰Zn + ²⁰⁸Pb → ²⁷⁷112 + 1n with a cross-section of ~1 picobarn.
Because the 112 isotope ultimately decays by a emission to known nuclei [namely isotopes of elements 102 (No) and 104 (Rf)], identification of this element is straightforward. Hot fusion reactions use more asymmetric beam and target nuclei, produce a compound nucleus with generally higher excitation energy that typically requires evaporation of three to five neutrons, generate more neutron-rich isotopes of an element, have lower survival probabilities with respect to fission, but have higher fusion probabilities. An example of this type of reaction is ⁴⁸Ca + ²⁴⁴Pu → ²⁸⁸114 + 4n with a cross-section of ~1 pb. Because of the neutron-richness of this isotope of element 114, it never subsequently decays to any known isotope, and thus its identification is more problematic. Cold fusion reactions have been successful in producing elements 104—112 and hot fusion reactions have recently provided evidence for elements 113—116 and 118.
6. What is a cyclotron?
A cyclotron is a particle accelerator that boosts ions to very high velocities through a series of small kicks as the ions travel in a circular motion (or spiral). The cyclotron was invented at the University of California, Berkeley, by Ernest O. Lawrence, the namesake of the Lawrence Livermore National Laboratory.                                                                                           CYCLOTRON   8. What is the “island of stability”?
The "island of stability" refers to a predicted region of superheavy elements on the chart of nuclides with half-lives that are longer by several orders of magnitude than the half-lives of other superheavy elements. Half-lives for elements in the island of stability may range from seconds to minutes, while half-lives for other superheavy elements may be measured in micro- or nanoseconds. The existence of the island of stability was shown in 1998 with the discovery of the superheavy element 114. The island of stability is a specific subset of the superheavy elements, which is characterized by nuclei that have a spherical shape.
9. What is the “sea of instability”?
The "sea of instability" refers to a region of elements on the periodic table that are highly unstable. These elements have extremely short half-lives that may be measured in micro- or nanoseconds. (A nanosecond is the time it takes for light to travel one foot.) This region of unstable elements surrounds the island of stability.
10. Why is discovering new superheavy elements important?
Discovering new superheavy elements proves long-held nuclear theories regarding the existence of the “island of stability” and the ultimate limits of the periodic table of the elements. These discoveries also help scientists to better understand how nuclei are held together and how they resist the fission process. The skills that are acquired by conducting these heavy-element experiments can then be applied to solving national needs like stockpile stewardship and homeland security. For example, an improved understanding of the fission process will enable scientists to enhance the safety and reliability of the nation’s nuclear stockpile and nuclear reactors.
11. How can superheavy elements be used?
Like most scientific discoveries, researchers do not yet know the immediate practical applications of the discovery of elements 113 and 115. Previously discovered heavy elements are used in smoke detectors (americium), neutron radiography and neutron interrogation (curium and californium), and nuclear weapons (plutonium). Scientists expect that practical applications of elements 113 and 115 also exist and will be discovered in the future.
12. How long did it take to discover elements 113, 114, 115, 116, and 118?

• Elements 113 and 115—The experiment began on July 14, 2003, and ended on August 10, 2003. In that time, four atoms of element 115 were produced that decayed after a given time, thereby producing element 113, which also decayed and so on. However, years of successful experiments, previous to the 115 and 113 discovery, were needed to show that the experiment could be successful. More than a year was then spent to clean the target material, ship it to Russia, make the target, and run the experiment.

• Element 114—The first element 114 experiment lasted about one year, and two atoms were discovered during that time.

• Element 116—The element 116 experiment also lasted about one year, and three atoms were discovered during that time.

• Element 118—Element 118 was produced during two separate experiments, each one lasting for several months. A total of three atoms were discovered in both experiements combined.

13. Why are the superheavy-element experiments conducted in Russia?
We collaborate with our Russian colleagues because we share a similar passion for the study of heavy elements, and we bring complementary skills and resources to the solution of magnificent problems such as the confirmation of the existence of the "Island of Stability" and the characterization of the chemical properties of exotic elements. This collaboration has been very fruitful and stimulating—enabling each group to achieve more in a shorter period of time. This equipment is operated by the highly trained scientific staff at the Dubna laboratory.
14. What special equipment is needed to discover superheavy elements?
There are three pieces of special equipment: 
(1) a cyclotron, which produces the intense beams of calcium-48 ions used to produce the superheavy elements; 
(2) a separator that separates the atoms of interest from everything else produced in these reactions; and
 (3) a detection system that can observe and record all of the events that take place during the experiment.
15. When will elements 113 and 115 be named?
We don't know when the elements will be named. The naming of new elements is a long process governed by the International Union of Pure and Applied Chemistry (IUPAC). Any discovery of new elements must first be confirmed by an independent laboratory and established beyond a reasonable doubt. Afterwards, the research team that discovered the element is asked to propose a name and symbol for the element. The proposed name is then reviewed by a panel of experts and, if all goes well, finally approved by the IUPAC. This naming process can take many years. For example, element 110 was discovered in 1995 and received its name, darmstadtium (Ds), in 2003, while element 106 was discovered in 1974 but was not officially named as seaborgium (Sg) until 1997. Until elements 113 and 115 receive their official names, they will be known by their temporary IUPAC names: ununtrium (Uut) for element 113 and ununpentium (Uup) for element 115.

What are isotopes? 

IIT JEE 2014

                         JEE Main 2014 Important Dates

The dates are as per the JEE Advanced Brochure released by IIT Kharagpur
Start of Online Application: November 15, 2013
Last date for Online Application:  December 26, 2013
JEE Main 2014 Test Date (Offline)

• Paper 1 - April 6, 2014 from 9.30 am to 12.30 pm
• Paper 2 – April 6, 2014 from 2 pm to 5 pm

JEE Main 2014 Test Date (CBT)

JEE Main 2014 Online Test Dates	Shifts per day
April 9, 2014	Shift 1: 9.30am to 12.30 pm Shift 2: 2pm to 5 pm if needed
April 11, 2014
April 12, 2014
April 19, 2014

Expected Date of Result: May 3, 2014
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Central Board of Secondary Education,
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Email: jeemain@nic.in
Helpline No: 011-8506061071 to 78

JEE Main 2014 criteria:

As rules changed so far, many of the students are confused regarding JEE main 2014 eligibility test criteria. Kindly read it carefully. 

• Age :  First qualification is age; jee board is considering strict rules on age. As per the last year those who are born after 1989 are eligible for jee main 2014 entrance test why because last year they considered October 1988 is the minimum year of age, below this year were disqualified for the jee main 2013 examination. For scheduled caste, tribe and PWD candidates there is age relaxation up to 5years has been given.
• Education: Students who passed in 2012 and 2013 are eligible for jee main 2014, there is no doubt about these students but for 2011 students we are not sure, we will update you once receiving the official notification from jee board. Candidates must have to pass 5 subjects and minimum aggregate marks should be 50 percent. 
• NoofAttemts: It is clearly informing that the number attempts to give the jee main 2014 examination is 3 times, beyond this are not eligible for the test.                                                                         

  What will be the exam pattern for IIT JEE 2014 ?

  Will the exam pattern for IIT JEE 2014 be the same as that of IIT JEE 2013?
  Well, we have the answer! IIT Bombay has proposed a new pattern for IIT JEE 2014.
  
  Yes, the new pattern proposed by IIT Bombay to JEE (advanced) will not have multiple choice questions (MCQ’s). The questions will be subjective, but students need not write long answers. They can solve the questions/problems and give the correct answers.The descriptive questions will be asked in the ” fill in the blanks” or  ”complete the following ” format.
  
  IIT-B director, Devang Khakhar said, “The proposed format is somewhere between the two formats. Students will not have to write long, descriptive answers. They will have to get answers on their own as there will be no options.
  
  ”The senates of other IIT’s are yet to approve the new IIT JEE 2014 exam pattern. It will then be presented at the joint admission board meeting.
  Well, what ever the pattern may it be; if your preparation is strong, you will definitely crack IIT JEE 2014. If getting into one of the IIT’s is your dream, then get started right now. The best time to begin your preparation is class 10. The early, the better always.
  
  First step of IIT JEE 2014 preparation is to recall your high school syllabus. Maths, Physics and chemistry. Refer to your old books if you have them or borrow it from your juniors/cousins. Go through the concepts, understand them so that you can relate to them once you start off the actual preparations for IIT JEE 2014. First thing that will come to your mind is the coaching classes. Your parents might also get the same thought. For IIT JEE 2014 preparations, self study is highly recommended.
  
  
  

  About JEE Main 2014 Exam

  
  

  
  It has been absolute to hold a JEE (Joint Entrance Examination) from the year 2014-15 for admission to the UG Under-Graduate programmes in Engineering in two portions, first is JEE-MAIN and second is JEE-Advanced Only the top 150000 applicants (including all groups) based on appearance in JEE MAIN will succeed to appear in the JEE-Advanced Exam. Admissions to IIT’s will be constructed only on category-wise All India Rank (AIR) in JEE-Advanced, focus to condition that such applicants are in the top 20 percentile groups. Admission to NIT’s will be centered on 40 % weightage for performance in 12th Standard board marks (normalized)   and the rest 60 % weightage would be assumed to performance in JEE Main and a mutual All India Rank (AIR) would be decided so. The policy could also be accepted by other Centrally Funded Technical Institutions (CFTI’s) and contributing Institutions.
  
  In case any State opts to acknowledge students in the Engineering Colleges allied to State Universities where States need separate merit grade to be provided based on comparative weightages accepted by the states, then the merit list shall be ready with such comparative weightages as may be specified by States. The examination will be lead in the Regional Languages of the State(s) on the needs of such State(s).
  
  
  
  

  JEE Main 2014 Exam Fee

  
  

  
  The following given table explains the exam fee (Indian rupees) based on the no. of papers that the student is appearing and mode of examination – Offline as well as Online examination:
  
  
  

  

  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  

 

Admission to NITs, IIITs, DTU, Delhi and other CFTIs

For NITs, IIITs, DTU, Delhi and other CFTIs – Merit List will consider 40% weightage for Class XII Exam and 60% to the performance in JEE (Main) Examination

For Admission to IITs, IIS , IT-BHU and Indian School of Mines

The admission to the undergraduate programmes at the IITs and ISMU, Dhanbad for the year 2014 will be based on a two-tier test. The first test called the JEE (Main), will be held during the month of April, 2014 (both offline and online). This test will be conducted by CBSE. The second test, called the JEE (Advanced), will be held on May, 2014 (only offline) as per IIT sources

Top  1.5 lakh  rankers of JEE (Main)  will be eligible for JEE Advanced earlier IIT JEE  ( from all categories (GE, OBC (NCL), SC and ST)

JEE MAIN 2014  PATTERN

The JEE (Main)-2014 (Paper I of earlier AIEEE) will have one objective type question paper. The paper will consist of Physics, Chemistry and Mathematics. The duration of the paper will be 3 (Three) Hours.

As it was in AIEEE, the JEE (Main)-2014 Paper II  for B.Arch/B.Planning admissions will have one Question Paper consisting of Mathematics, Aptitude Test and Drawing Test. The duration of the paper will be 3 (Three) Hours.

JEE ADVANCED 2014 PATTERN

The JEE Advanced 2014 will have two objective type papers.

Each paper will consist of Physics, Chemistry and Mathematics.

Duration of each paper will be 3-hours.

Question papers will be in both English and Hindi.

Admissions to IITs will be based only on category wise All India Rank (AIR) in JEE (Advanced) subject to the condition that such candidates are in the top 20 percentile of successful candidates of their Boards in applicable categories.