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Synthesis_of_Elements_with_Final_Speaker_Notesgjkh
- 2. Objectives: 1. Explaintheconceptofatomicnumberanditsrole intheperiodictable. 2. Developatimelineofthediscoveryandsynthesis ofnewelements. 3.Reflectonthesignificanceofsynthesizingnew elementsandtheirimpactonscientificadvancement
- 3. What is anAtom? An atom is the smallest unit of matter that retains the properties of an element.
- 4. Structure of anAtom Nucleus contains protons (positively charged) and neutrons (neutral). Electrons (negatively charged) orbit the nucleus in energy levels. The arrangement of electrons determines chemical behavior.
- 5. Definition of Terms Proton:Positively charged particle in the nucleus. Neutron: Neutral particle in the nucleus. Electron: Negatively charged particle orbiting the nucleus. Nucleus: The dense center of the atom containing protons and neutrons.
- 10. The Discovery of ATOMand the concept of Atomic Number
- 12. • In 1897,JJ Thompson was working on cathode ray tubes. • In his experiments he discovered the presence of a negatively charge particle inside an atom. He called them “CORPUSCLES” but now we call them “ELECTRONS”. He thought that this negatively charge particles were embedded in a positively charge atom.
- 13. •This was provenwrong when in 1911 Ernest Rutherford did the GOLD FOIL EXPERIMENT. He took a very thin gold foil and bombarded it with alpha particles he then surrounded it with a screen that could detect alpha particles.
- 14. Conclusions of Rutherford’sGold foil Experiment: •Most of the atom is empty space. •He also observed that some of the alpha particles were deflected side ways and some bounce
- 15. Conclusions of Rutherford’sGold foil Experiment: •He concluded that the positive charge is concentrated at the center while the negative charge orbit around it like how planets orbit around the sun. That is how he discovered the NUCLEUS.
- 16. • Back then,they imagine the atom to have a positively charge nucleus with electron orbiting around it. • Soon Ernest Rutherford discovered that the nucleus of an atom is made up of positively charge subatomic particles called PROTONS.
- 17. •In 1932, JamesChadwick (who was a student of Ernest Rutherford) did an experiment with alpha particles and beryllium atom. • He fired beryllium with alpha particle. A form of radiation was produced. He observed that this was the same mass as proton but has no charge. He later called these NEUTRONS.
- 18. Atomic Mass or MassNumber – total of Proton & Neutron in an element.
- 19. The Missing Link:The Holy Grail of Synthetic Elements
- 20. How are theelements in the periodic table organized in each period? •Sir Henry Moseley discovered that the properties of the elements vary periodically with the atomic number, and not with the atomic weight previously accepted under Mendeleev’s atomic mass principle.
- 21. • With theuse of x-ray spectroscopy, he was able to determine the atomic number of an element. • In the process, a beam of electrons is bombarded causing x-ray spectral lines to come out of the elements. His quantitative results proved that the frequency of the x- rays given off by an element is directly related to the position of the element in theperiodic
- 22. Atomic Number – refersto the number of proton in an element.
- 23. How Are ElementsSynthesizeIn The Laboratory?
- 24.
- 25. • In 1937,two Italian scientist Carlo Perrier & Emilio Segre discovered the element 43. • Greek word “Tekhnetos” means “artificial”. 43 T c Technetiu m
- 26. •They bombarded deuteron(isotope of hydrogen with 1 proton and 1 neutron) by Molybdenum. •When this deuteron hits molybdenum its proton is attached in the nucleus and neutrons are emitted. The addition of 1 proton resulted into element 43 or “Technicium”. = Deuteron Molybdenum “Technicium” +
- 27. 2𝐻 + 97𝑀𝑜→ 21𝑛 + 97 𝑇𝑐 1 42 0 43 Nuclear Reaction on the creation of element “TECHNICIUM” Combination of deuteron and molybdenum • no. of protons • no. of neutrons • Mass no. Mass number (proton + neutron) Atomic number (no. proton)
- 29. ISOTOPE NOTATION Atomic Number/ Total no. ofProtons Mass Number/ Total no. of Protons and Neutrons
- 30. 85 At Astatine •In 1940, DaleR. Corson, Kenneth Ross McKenzie & Emilio Segre discovered the element 85. •They used cyclotron to collide alpha particle with bismuth.
- 31. •A cyclotron isa circular machine that accelerates particle or nuclei to collide them with other nuclei. • The cyclotron makes sure that the particles are moving fast enough to overcome electrostatic repulsion between atoms.
- 32. 209 𝐵𝑖 + 4 𝐻𝑒→ 211 𝐴𝑡 + 21𝑛 Nuclear Reaction on the creation of element “ASTATINE” = 𝛼 𝑝𝑎𝑟𝑡𝑖𝑐𝑙 𝑒 Bismuth “Astatine” +
- 34. •In the early1940, Edwin Mcmillan and Philip Abelson discovered the TRANSURANIUM ELEMENTS (elements heavier than uranium)
- 35.
- 36. 93 Np Neptunium • Neptunium wasthe first synthetic transuranium element (elements after uranium) of the actinide series to be discovered. • Neptunium is harmful due to its radioactivity.
- 37. 238𝑈 + 1𝑛→ 239𝑁𝑝 + 0𝛽 Nuclear Reaction on the creation of element “NEPTUNIUM” 92 0 93 −1 •Atoms that have too many neutrons compared to proton have greater tendency to undergo beta decay (1 neutron turn into proton and then beta particle is release)
- 38. 94 Pu Plutonium •Plutonium was firstproduced and isolated on December 14, 1940 by Dr. Glenn T. Seaborg, Joseph W. Kennedy, Edwin M. McMillan, and Arthur C. Wahl by deuteron bombardment of uranium in the 60- inch cyclotron at the University of California, Berkeley.
- 39. 94 Pu Plutonium • plutonium (Pu),radioactive chemical element of the actinoid series of the periodic table, atomic number 94. • It is the most important transuranium element because of its use as fuel in certain types of nuclear reactors and as an ingredient in nuclear weapons. • Plutonium is a silvery metal that takes on a yellow tarnish in air.
- 40. Uranium 238 : 92protons 146 neutrons Uranium 239 : 92 protons 147 neutrons Neptunium 239 : 93 protons 146 neutrons Plutonium 239 : 94 protons 145 neutrons
- 41. •Element 95 was synthesizeby neutron capture. Two neutrons was absorbed by element 94 then 1 neutron turns into proton. 95 Am Americium
- 42. 96 Cm Curium 97 Bk Berkelium •Elements 96,97,98 &101 was synthesize by alpha particle bombardment in cyclotron. 98 Cf Californium 101 Md Mendelevium
- 43. •The discovery ofthe elements 99 & 100 was interesting they were found from the debris of hydrogen bomb explosion. The energy from the blast made neutron capture possible which resulted to the synthesis of many elements including elements 99 & 100. 99 Es Einsteinium 100 Fm Fermium
- 44. •Elements heavier thanelement 103 are considered super heavy elements. They are usually produce or synthesize by bombarding heavy nuclear target with heavy projectiles.
- 45. • Nihonium – Nihonis one way to say “Japan” in Japanese. As this was the first element discovered by an Asian country, Japan wanted the name to represent the geographical region. Nihon means “the Land of Rising Sun” and provides a direct connection to Japan as a nation.
- 46. • Moscovium – Moscovium also representsa geographical region, specifically, the Moscow region which is where the discovery experiments were conducted.
- 47. • Tennessine – Tennessine recognises thelaboratories that contribute to element research in the Tennessee region which include Oak Ridge National Laboratory, Vanderbilt University, and the University of Tennessee in Knoxville.
- 48. •It was preparedby the bombardment of berkelium and calcium. •Since only a few atoms of tennessine have ever been produced, it currently has no uses outside of basic scientific research. 117 T s Tennessin e
- 49. • Oganesson – Oganesson attributedits name to a scientist following the IUPAC naming convention. Professor Yuri Oganessian (born 1933) is a Russian nuclear physicist who is credited with three confirmed
- 50. •The heaviest elementknown so far is element 118 (Oganesson). It was made through the bombardment of californium with calcium. •It is a radioactive synthetic transactinide element, officially recognized in 2016. Since 2005, only 4 atoms of oganesson have been produced, so there is much to learn about this new element. 118 Og Oganesson
- 51. •The name recognisesthe Russian nuclear physicist Yuri Oganessian for his contributions to transactinide element research. •At present, it is only used in research. It has no known biological role. 118 Og Oganesson
- 52. CHALLENGES IN CREATINGELEMENTS HEAVIER THAN ELEMENT 118 •If you want to create element heavier than Oganesson. You can try to bombard Calcium and Einstenium .But the problem is the scarcity of Einstenium. •Only a few atoms of the synthetic element have ever been created, each of which survived for less than a millisecond. So to investigate oganesson’s properties, scientists have to rely largely on theoretical predictions.
- 53.
- 54. What is NUCLEARTRANSMUTATION? •Transmutation or nuclear transmutation is a process that involves a change in the nucleus of an atom. • When the number of protons in the nucleus of an atom changes, the identity of that atom changes as it is turned into another element or isotope. This transmutation process
- 55. There are threemain types of nuclear reactions: 1.NUCLEAR FUSION: this is the joining of two small atomic nuclei into one nucleus. 2.NUCLEAR FISSION: this is the splitting of one large atomic nucleus into smaller fragments. it does not occur by itself. Neutrons are bombarded on a heavy nucleus.
- 56. There are threemain types of nuclear reactions: 3. RADIOACTIVE DECAY: this is the change of a less stable nucleus to a more stable nucleus. It is a spontaneous process and occurs by itself.
- 57. Atoms may undergoany of the three known radioactive decay processes:
- 59. •Suppose you aregiven three radioactive cookies -- one an alpha emitter, one a beta emitter, one a gamma emitter. You must eat one, hold one in your hand, and put the other one in your pocket. ANSWER: eat the gamma; hold the alpha in your hand; put the beta in your pocket
- 60. 1. ALPHA DECAY-nucleus emits alpha particle (+), with 2 protons and 2 neutrons Pb
- 61. 2. BETA DECAY-nucleus emits an electron (-) /beta minus or beta plus (positron)
- 62. 3. GAMMA DECAY-nucleus emits the highest energy photons, gamma rays (0)
Editor's Notes
- #1 Today, we’ll explore how scientists discovered and created new elements in laboratories. We’ll trace how our understanding of atoms developed over time. This topic connects chemistry, physics, and the human drive to uncover the unknown.
- #2 Our goal today is to understand the atomic number, how elements were discovered, and why synthesizing new ones matters. These ideas will help us see how science builds upon earlier discoveries. By the end, we’ll appreciate how new elements expand human knowledge and technology.
- #3 An atom is the fundamental building block of matter. It contains a nucleus made of protons and neutrons, with electrons orbiting around it
- #4 The central nucleus contains protons and neutrons, while electrons orbit in shells. The number of protons and electrons defines the element’s properties.
- #5 The central nucleus contains protons and neutrons, while electrons orbit in shells. The number of protons and electrons defines the element’s properties.
- #6 Democritus (400 BCE) – He was the first to suggest that all matter is made up of small, indivisible particles called “atomos.” He believed atoms could not be divided into smaller parts forever. John Dalton (1803) – He created the first atomic theory, describing atoms as tiny, solid spheres (like billiard balls). Dalton said each element is made of identical atoms that combine in fixed ratios to form compounds. J.J. Thomson (1897) – He discovered the electron, showing that atoms are made of smaller particles. His model, called the “plum pudding” or “raisin bun” model, depicted electrons scattered within a positively charged sphere. Ernest Rutherford (1911) – He conducted the gold foil experiment and found that atoms have a dense, positively charged nucleus at the center, surrounded by mostly empty space. This led to the nuclear model of the atom. Niels Bohr (1913) – He improved Rutherford’s model by proposing that electrons orbit the nucleus in specific energy levels or shells, much like planets orbit the sun. This became known as the Bohr model. James Chadwick (1932) – He discovered the neutron, a neutral particle inside the nucleus, which explained the atom’s total mass. Modern Atomic Model (1920s–present) – Modern scientists describe electrons as moving in clouds around the nucleus rather than fixed orbits. This quantum model explains that we can only predict the probable location of an electron, not its exact path.
- #7 The modern periodic table organizes elements by their atomic number. This arrangement shows repeating trends in their properties. It’s the foundation of chemistry and a roadmap for discovering new elements.
- #8 🟡 Non-synthetic elements (natural) These elements exist naturally on Earth. They are found in nature — in rocks, air, water, and living things. Example: Oxygen (O), Carbon (C), Iron (Fe), Gold (Au). They are colored yellow in the chart. 🔴 Synthetic (pure) elements These elements do not exist naturally — scientists make them in laboratories or nuclear reactors. They are man-made and usually radioactive (they decay quickly). Example: Technetium (Tc), Promethium (Pm), Plutonium (Pu), and all elements with numbers 93 and above. They are colored red in the chart. 🩵 Synthetic (usually) elements These elements sometimes occur naturally in tiny amounts but are mostly made by scientists because they are very rare and unstable. Example: Francium (Fr) and Astatine (At). They are colored blue in the chart.
- #9 Dmitri Mendeleev organized elements by atomic mass and predicted the existence of unknown ones. His system revealed patterns that shaped the modern periodic table. Although later refined, his work remains a cornerstone of chemistry.
- #10 Early scientists believed atoms were indivisible, but later research proved otherwise. The discovery of subatomic particles changed how we understand matter. The atomic number became the key to identifying each element.
- #11 Thomson, Rutherford, and Chadwick uncovered the main building blocks of the atom. Their discoveries of the electron, proton, and neutron revealed the atom’s structure. This work laid the groundwork for modern atomic theory.
- #12 In 1897, J.J. Thomson discovered the electron using cathode ray tubes. He proved atoms contain small, negatively charged particles. This was the first evidence that atoms are divisible. If something is divisible, it can be split or separated into smaller parts. If it is not divisible, it cannot be broken down any further.
- #13 Rutherford’s gold foil experiment revealed a dense, positively charged center in atoms. This nucleus contained protons, defining each element’s identity. His discovery reshaped the atomic model completely.
- #14 Alpha particles are a type of radiation made up of 2 protons and 2 neutrons — the same as a helium nucleus. When some unstable atoms (radioactive elements) break down, they release alpha particles. These particles are positively charged because they have protons but no electrons. Most alpha particles passed through gold foil, showing atoms are mostly empty space. A few bounced back, proving a dense center existed. This led scientists to identify the atomic nucleus.
- #15 Rutherford concluded that an atom’s positive charge and mass are concentrated in a nucleus. Electrons orbit around it, much like planets around the sun. This model became the basis for atomic science.
- #16 Rutherford’s model showed electrons revolving around a central nucleus. The nucleus held positively charged protons, giving atoms their identity. This visualization helped explain atomic stability and behavior.
- #17 In 1932, James Chadwick discovered the neutron through experiments with alpha particles and beryllium. Neutrons had mass but no charge, balancing the nucleus’s structure. This completed the model of subatomic particles.
- #18 The atomic mass is the total number of protons and neutrons in an atom’s nucleus. These two particles make up nearly all its mass. Understanding this helps explain isotopes and element stability.
- #19 Scientists began searching for elements that could be made artificially. This pursuit led to the discovery of synthetic elements beyond uranium. It marked a major breakthrough in nuclear chemistry.
- #20 Sir Henry Moseley discovered that atomic number, not atomic mass, defines an element’s identity. His work using X-ray spectroscopy corrected earlier inconsistencies. This firmly established the modern structure of the periodic table.
- #21 Moseley bombarded elements with electrons and analyzed their X-ray emissions. He found a clear relationship between X-ray frequency and atomic number. This confirmed that atomic number is the true basis for element organization.
- #22 The atomic number represents the number of protons in an atom’s nucleus. It determines the element’s identity and position in the periodic table. Every element is unique because of its proton count.
- #23 Now we’ll look into how scientists actually create new elements inside laboratories. These processes often involve colliding atomic nuclei under controlled conditions. It’s through these experiments that scientists discovered many elements beyond uranium.
- #24 Before World War II, uranium was the heaviest known natural element on the periodic table. Scientists believed that elements heavier than uranium couldn’t exist naturally. This belief changed when new experimental techniques allowed the creation of artificial elements.
- #25 In 1937, Italian scientists Carlo Perrier and Emilio Segrè successfully created element 43, called Technetium. Its name comes from the Greek word Tekhnetos, meaning 'artificial.' This was the first man-made element ever synthesized in a laboratory.
- #26 Technetium was formed by bombarding molybdenum with deuterons, which are hydrogen atoms containing one proton and one neutron. The collision added a proton to the nucleus and released neutrons, producing Technetium. This experiment marked the beginning of synthetic element research.
- #27 Here we see the nuclear equation representing Technetium’s creation. It shows how deuterium and molybdenum combine to form a new element while releasing neutrons. This equation became the model for future element synthesis. So, the 2 neutrons appear because the nucleus “spits them out” to stabilize itself after the collision — a common process in nuclear reactions.
- #29 Isotope notation helps identify atoms with the same number of protons but different numbers of neutrons. The top number represents the mass number, while the bottom shows the atomic number. This system makes it easy to write nuclear reactions clearly and accurately.
- #30 In 1940, Dale Corson, Kenneth McKenzie, and Emilio Segrè discovered the element Astatine. They used a cyclotron to bombard bismuth with alpha particles. This resulted in the creation of a new radioactive element with atomic number 85.
- #31 The cyclotron is a powerful machine that accelerates charged particles to high speeds. It allows scientists to collide nuclei with enough energy to overcome repulsion between them. This tool became essential in the production of synthetic elements.
- #32 This equation shows how alpha particles collide with bismuth to produce Astatine and two neutrons. The process demonstrates how new elements can be created through controlled nuclear reactions. It’s a clear example of artificial element synthesis.
- #33 After Astatine and Technetium were discovered, the periodic table expanded beyond uranium. Scientists realized that new elements could be continuously added through laboratory work. This period marked the transition from natural to synthetic chemistry.
- #34 In the early 1940s, Edwin McMillan and Philip Abelson discovered the transuranium elements, which are heavier than uranium. These elements do not occur naturally and must be created in nuclear reactors or particle accelerators. Their discovery opened the door to an entirely new group on the periodic table.
- #35 Here you can see where the transuranium elements appear on the periodic table. They occupy the actinide series, following uranium. Each of these elements was discovered through experiments involving nuclear bombardment.
- #36 Neptunium was the first synthetic transuranium element to be identified. It was produced when uranium absorbed a neutron and emitted a beta particle. Because of its radioactivity, it is primarily used for scientific study rather than practical applications.
- #37 This equation shows how uranium-238 captures a neutron and transforms into neptunium-239. The process involves beta decay, where a neutron converts into a proton and emits an electron. This was one of the first examples of nuclear transformation in the lab.
- #38 Plutonium was first produced in 1940 by Glenn Seaborg and his team at the University of California, Berkeley. They used a cyclotron to bombard uranium with deuterons, creating a new, highly radioactive element. Plutonium later became one of the most important materials for nuclear energy and research.
- #39 Plutonium is a radioactive metal and one of the most important transuranium elements. It was discovered as part of the actinide series and is used in nuclear reactors and weapons. In air, it forms a yellowish tarnish, showing how reactive it is.
- #40 This slide shows how plutonium-239 forms through a sequence of nuclear reactions. Uranium absorbs a neutron to form neptunium, which then decays into plutonium. These transformations demonstrate how one element can change into another through neutron capture and decay.
- #41 Americium was created through neutron capture when two neutrons were absorbed by plutonium. One of the neutrons turned into a proton, forming a new element. This element is commonly used today in smoke detectors and scientific instruments.
- #42 Elements 96, 97, 98, and 101 were all synthesized using alpha-particle bombardment in a cyclotron. These discoveries expanded the periodic table even further into the actinide series. Each new element confirmed that artificial synthesis could continue beyond natural atomic limits.
- #43 Elements 99 and 100 were discovered in the debris of a hydrogen bomb explosion. The intense energy allowed atoms to capture more neutrons, forming new elements. This event proved that extreme conditions can lead to the creation of entirely new matter.
- #44 Elements heavier than 103 are called superheavy elements. They are created by bombarding heavy atomic nuclei with other heavy particles. These elements are highly unstable and exist only for fractions of a second before decaying.
- #45 Nihonium was the first element discovered by scientists in Japan. Its name comes from 'Nihon,' meaning 'Land of the Rising Sun,' symbolizing Japan’s achievement in element discovery. It marked a proud milestone for Asian contributions to modern chemistry.
- #46 Moscovium was named after the Moscow region where it was discovered. The name honors the scientists and laboratories in Russia that contributed to element synthesis. It shows how geography and collaboration play roles in scientific progress.
- #47 Tennessine was created through the bombardment of berkelium and calcium. It was named after the U.S. state of Tennessee, home to several major research institutions. Because only a few atoms have been made, it currently has no practical use outside of research.
- #48 Oganesson is the heaviest element discovered so far, created by bombarding californium with calcium. It was named in honor of Russian physicist Yuri Oganessian, who contributed greatly to element research. So far, only a few atoms have been produced, and scientists continue to study its properties.
- #49 Nuclear transmutation is the process of changing one element into another by altering its atomic nucleus. This can occur naturally through radioactive decay or artificially in laboratories. It’s the principle behind both element synthesis and nuclear energy research.
- #50 Oganesson is the heaviest element known so far and was created by bombarding californium with calcium. It’s a synthetic, radioactive element recognized officially in 2016. Since only a few atoms have been made, scientists are still studying its properties.
- #51 Oganesson was named after Yuri Oganessian, a Russian physicist known for his contributions to element research. It currently has no known biological use and is studied purely for scientific understanding. Its discovery represents the frontier of modern element synthesis.
- #52 Creating elements heavier than Oganesson is extremely difficult because the target materials are rare and unstable. Scientists face challenges due to the scarcity of Einsteinium and short lifespans of these new atoms. Most research now relies on theoretical predictions rather than direct experiments.
- #53 Now we move into nuclear transmutation — how one element can change into another. This concept connects everything we’ve discussed about element formation. It’s a key process behind both natural and artificial creation of new elements.
- #54 Nuclear transmutation happens when the number of protons in an atom’s nucleus changes. This process alters the atom’s identity, turning it into a different element. It can occur naturally through radioactive decay or artificially in laboratory experiments.
- #55 There are two main types of nuclear reactions: fusion and fission. Fusion joins two small nuclei into one larger nucleus, like in the sun. Fission splits a heavy nucleus into smaller parts, releasing a huge amount of energy.
- #56 Radioactive decay is the natural process where unstable atoms become more stable over time. It occurs spontaneously, producing radiation as a byproduct. This process explains how some elements slowly transform into others in nature.
- #57 Atoms can undergo alpha, beta, or gamma decay depending on their structure. Each type changes the nucleus in a different way. These decays are key to understanding how matter changes at the atomic level.
- #58 This slide acts as a short pause before diving into the specific types of decay. It reminds us that all nuclear changes involve the nucleus, not the electrons. It helps transition smoothly into the next detailed section.
- #59 This is a fun example to remember radiation safety concepts. It compares alpha, beta, and gamma emitters to cookies you could eat, hold, or keep in your pocket. The idea helps visualize which types of radiation are more penetrating or dangerous.
- #60 Alpha decay occurs when the nucleus releases an alpha particle, made of two protons and two neutrons. This process decreases both the atomic and mass numbers of the atom. It’s the least penetrating but most massive form of radiation.
- #61 In beta decay, a neutron changes into a proton and emits an electron or positron. This increases or decreases the atomic number by one, depending on the type of beta decay. Beta radiation can penetrate farther than alpha particles but is still stopped by shielding.
- #62 Gamma decay emits high-energy photons known as gamma rays. Unlike alpha or beta decay, it doesn’t change the atom’s composition but releases excess energy. Gamma radiation is the most penetrating and requires thick materials for protection.
- #63 This slide compares gamma rays to other forms of electromagnetic radiation. Gamma rays have the shortest wavelength and highest energy, making them powerful but dangerous. They are useful in medicine, research, and sterilization when properly controlled.