Atomic Number and Synthesis of New Elements PDF

Summary

This document explains the concept of atomic number and its role in the synthesis of new elements. It details nuclear reactions and particle accelerators used for this process. It also introduces transuranium elements and relevant historical figures.

Full Transcript

The Atomic Number and the Synthesis of New Elements At the end explain how the concept of of the lesson, you atomic number led to the 1 synthesis of new elements should be able to: in the laboratory. An element is the simplest substance. It is...

The Atomic Number and the Synthesis of New Elements At the end explain how the concept of of the lesson, you atomic number led to the 1 synthesis of new elements should be able to: in the laboratory. An element is the simplest substance. It is composed of one atom only. The elements discovered on earth or synthesized by scientists in the laboratory are listed in the periodic table. A nuclear reaction is needed to synthesize elements. Atoms can be fused together or these can split into two different atoms. These nuclear reactions obey the Law of Conservation of Mass as it was explained and used by the atomic theory. Atoms are neither created nor destroyed. These are merely modified by splitting, rearranging and combination of the nucleons (protons and neutrons.) Review Chemical Equation A chemical equation is a written representation of a chemical reaction. CHEMICAL COEFFICIENTS FORMULA 2H2 + O2 REACTION ARROW 2H2O REACTANTS PRODUCTS SUBSCRIPTS Atoms that combine together will form a compound. However, atoms that have their nuclei combine will form another atom. Scientists Explained the Structure of the Atom Dalton’s Billiard Ball Model Thomson’s Plum Pudding Model Rutherford’s Planetary Model Bohr’s Model of the Hydrogen Atom Schrodinger’s Electron Cloud Model Scientists Explained the Structure of the Atom THE ARRANGEMENT OF THE ELEMENTS Johann Dobereiner made use of Triads. John Newlands made use of Octaves. Dmitri Mendeleev arranged elements by increasing atomic weights.He is considered as the Father of the Periodic Table. Henry Moseley made use of spectroscopic data that lead him to arrange elements by increasing atomic number. Atomic Number The atomic number is also known as the Z number. The Z came from the German word, “Zahl.” It means number. The atomic number corresponds to the number of protons. The number of protons gives the identity of the atom. Nuclear Transmutation Reactions was Possible Knowledge of the atomic number introduced nuclear reactions Transformation of one element or isotope into another element. The reaction includes protons and neutrons. Ernest Rutherford did the First Nuclear Transmutation Reaction using an Alpha Particle Nuclear Transmutation Reactions Alpha particles are positively charged and the nucleus will repel it. Neutrons were then used instead of the the alpha particle. Particle Accelerators To overcome the repulsion between the nucleus and alpha particles, particle accelerators were used. The alpha particles were made to move in a very fast way which will overcome repulsive forces. A cyclotron is a particle accelerator that uses alternating electric field to accelerate particles that move in a spiral path in the presence of a magnetic field. Cyclotron Particle Accelerators were Used to Synthesize Elements Lawrence synthesized Technetium. Segre, Mackenzie and Corson synthesized Astatine. Transuranium Elements Uranium was the heaviest known element by 1930. Its atomic number is 92. Elements having an atomic number of greater than 92 are known as transuranium elements. Transuranium elements are synthesized using particle accelerators. TAKE NOTE! Atomic number, Z, is the number of protons in an 1 atom. It is identical to the charge number of the nucleus. It uniquely identifies a chemical element. Henry Gwyn Jeffreys Moseley discovered that the 2 periodic table of elements should be arranged based on its atomic number. TAKE NOTE! A particle accelerator is used to synthesize new 3 elements. A cyclotron is a particle accelerator that uses alternating electric field to accelerate particles that 4 move in a spiral path in the presence of a magnetic field. Identify what or who is being asked on the following statements. 1.He is an English physicist who arranged the periodic table using the atomic number. 2.It is a device that is used to speed up particles to overcome the repulsion between the particles and the target atomic nuclei by using magnetic and electrical fields. 3.It is a particle accelerator that uses alternating electric field to accelerate particles that move in a spiral path in the presence of a magnetic field. Is it still to possible to synthesize new elements using advanced particle accelerators nowadays? Why? Why not? Chang, Raymond. 1997. Chemistry. New York: McGraw-Hill. Charley, S. “How to Make an Element.” Accessed January 5, 2017, http://www.pbs.org/wgbh/ nova/physics/make-an-element.html. McQuarrie, D.A., and Rock, P.A. 1991. General Chemistry. 3rd ed. New York: W.H. Freeman. Watson, G.W. “A Brief History of Element Discovery, Synthesis, and Analysis.” Open Knowledge Project. Accessed January 5, 2017, http://in.okfn.org/files/2013/07/A-BriefHistory-of-Element- DiscoverySynthesis-and-Analysis.pdf. 2011. Encyclopedia of Trivia. Accessed July 17, 2018. https://encyclopaediaoftrivia.blogspot.com/2011/08/aristotle.html. Feder, Michelle. 2018. Khan Academy. Accessed July 17, 2018. https://www.khanacademy.org/partner- content/big-history-project/stars-and-elements/other-material3/a/from-alchemy-to-chemistry. Schelenz, Robin. 2018. University of California. April 10. Accessed July 17, 2018. https://www.universityofcalifornia.edu/longform/how-ernest-o-lawrences-aha-moment-led-nuclear- physics. n.d. WAYNE RESA. Accessed July 17, 2018. http://www.resa.net/curriculum/curriculum/science/curriculum/chemistry/unitdoc/unit1/. 2018. Core Concepts: Periodic Table. Accessed July 18, 2018. http://periodictable.rosendigital.com/staticfiles/reproducibles/Introducing_Lesson.pdf. 2018. "Center for Nuclear Science and Technology Information." nuclearconnect.org. Accessed July 20, 2018. Center For Nuclear Science and Technology Information. (2018). Retrieved from nuclearconnect.org: http://www.nuclearconnect.org/in-the-classroom/for-teachers/classroom- activities. Gill, N.S. 2017. ThoughtCo. March 08. Accessed August 09, 2018. https://www.thoughtco.com/philosophy- of-atomism-120427.

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