The discovery of radioactivity in 1896 by Henri-Antoine Becquerel (1852-1908) opened the door for a whole new group of unstable elements. However, a difficulty emerged – a glut of elements was appearing; each with a different half-life, yet many had similar, if not identical, chemical properties. With no room left in the Periodic Table, confusion reigned supreme.
Frederick Soddy (1877-1956) clarified the situation in 1913 with his concept of isotopes, demonstrating that some elements could have different half-lives and yet have identical chemical behavior – hence, they were in the "same place" (from the Greek "isos topos") in the Periodic Table. When the neutron was discovered by James Chadwick (1891-1974) in 1932, the source of the isotopes became clear – isotopes have the same atomic number, but different atomic mass.
The history of the elements ever since has been the discovery – mostly through designed nuclear reactions – of a score of additional elements (with many different isotopes), making the present grand total of 118 in the modern Periodic Table.
Explore the elements by decade:
- 1935-1944: Technetium, Francium, Astatine, Neptunium, Plutonium, Americium, Curium
- 1945-1954: Promethium, Berkelium, Californium, Einsteinium, Fermium
- 1955-1964: Mendelevium, Nobelium, Rutherfordium
- 1965-1974: Dubnium, Seaborgium, Lawrencium
- 1975-1984: Bohrium, Meitnerium, Hassium
- 1985-1994: Darmstadtium, Roentgenium
- 1995-2004: Copernicium, Flerovium, Livermorium, Nihonium
- 2005-2019: Tennessine, Oganesson, Moscovium
Read more about "The Radioactive Elements" in the Chem 13 News article by James Marshall.
1935-1944: Technetium, Francium, Astatine, Neptunium, Plutonium, Americium, Curium
Technetium, 43
Huron Heights Secondary School (HHSS)
Kitchener, Ontario, Canada
Teacher: Craig Matthews
Artists: Lakyn Hann, Stefan Djukic, Ria Menon
The colour of the symbol, number, and mass reflects the silver grey colour of the element. The tri-colour background, the Italian country of discovery, along with the names of the discoverers, and the date and the five full and partial stars to the discovery of 'technetium stars' containing a high content of the element, as well as the five valence electrons in the 4d suborbital. The hand is included to symbolize technetium being a person-made element on earth and used for medical imaging. The radiation symbol represents its radioactive instability.
Francium, 87
Port Credit Secondary School
Mississauga, Ontario, Canada
Teacher: Jeanne Honsberger
Artist: Massa Mohamed Ali
Francium was discovered by Marguerite Catherine Perey, a French chemist, in 1939. To represent its radioactive and unstable properties, I drew an explosion, along with hazard symbols in the background. Since the element is named after France, I chose to personify it by making it hold a baguette and wear a hat. I also used the colours of the French flag. I made francium hold a scroll to symbolize the different claims and denials made by scientists about francium before Perey. The scroll represents Perey's extensive research and experimentation, which led to its discovery.
Astatine, 85
Quezon City Science High School
Quezon City, Quezon City, Philippines
Teacher: Richard Sagcal
Artist: Radioactive
Astatine being a radioactive element is symbolized by a trefoil on Emilio Segre's eyes (discoverer of astatine) on the oil painting. The trefoil or the international radiation symbol also acts as the nucleus or the center of the element's electron shell structure. The number 85 can also be seen which is astatine's atomic number. The electron shell structure served as the centre figure of the larger trefoil. The color orange was used instead of yellow to symbolize creativity and enthusiasm, critical to scientific discoveries.
Neptunium, 93
Victoria Shanghai Academy
Hong Kong, Hong Kong
Teacher: Isabella Liu
Artists: Jane Chan, Cherilynne Chau, Sammie Srirotjariya, Kaitlyn Chan, Charmaine Wan, Alicia Yu
When we first were assigned the element, students brainstormed related keywords and colours that would be associated to neptunium, which was named after the planet Neptune. Because Neptune is the next planet beyond Uranus, the name neptunium made sense as it is the next element on the periodic table after uranium. The keywords blue, ocean, and the God of Neptune, kept reoccurring, which was why the final element tile contained aspects of the water god, dragons, and his famous trident. Neptunium was discovered by Edwin McMillan and Philip Abelson in 1940.
Plutonium, 94
Rye High School
Rye, New York, USA
Teacher: Sally Mitchell
Artist: Naomi Melia Saito
Plutonium element was discovered by Glenn Seaborg and his team by producing plutonium using the cyclotron when they bombarded Uranium-238 with deuteron particles. The first cyclotron was invented by Ernest O. Lawrence. (My teacher was the last person to touch it before it was locked up.) Plutonium was named after the planet, Pluto. Trinity was the code name for the very first detonation of a nuclear bomb on July 16, 1945 in New Mexico. Plutonium bombs create a pyrocumulus mushroom cloud. It is highly radioactive, and the symbol was also invented at the University of California Berkeley.
Americium, 95
The Steward School
Richmond, Virginia, USA
Teacher: Leslie Kovach
Artists: Allison Langenburg, Anna Reese Richardson, Alex Wilkerson, Zayd Rehman
Our image depicts the four scientists who discovered the element riding an atomic bomb in outer space. The atomic bomb represents the actual discovery of the element. During WWII, the scientists were testing the bombs when they produced americium. The element is now tested for use in the international space station, hence the picture being set in outer space.
Curium, 96
Hants North Rural High
Kennetcook, Nova Scotia, Canada
Teacher: Jodi Davis
Artists: Adyson Singer, Arianna Lyons, Hannah Rines
Polonium and Radium are included because Marie Curie discovered these elements. The radioactive symbol is there because Marie Curie worked with radioactive elements. Since Marie was from Poland and her husband Pierre was from France, we chose to include the flags from those countries. The rings signify the love and marriage between Marie and Pierre. 1944 was the year curium was discovered. Green is the background because that was Marie's favourite colour. The initials of our school are also included.
Promethium, 61
Pemberton Secondary School
Pemberton, British Columbia, Canada
Teacher: Karen Tomlinson
Artists: Kate Brosseau, Arriya Kuiper, Belle Dorgelo
Each artist contributed to different parts of the artwork. The stars are the Andromeda constellation, where traces of Promethium are found. Promethium was given its name from the Greek Titan Prometheus who stole fire from the gods to give to the humans. Prometheus' torch holds the star in the constellation where Promethium was found. The lake colour is symbolic of the chemical compound of promethium-145 in luminous paint, and the power plants represent how promethium is not naturally occurring on Earth, but must be manufactured. The mountain in the background is Mount Currie, which overlooks our town of Pemberton.
Berkelium, 97
Georgian Bay District Secondary School
Midland, Ontario, Canada
Teacher: Dr. Stacey Deneka
Artist: Abhimanya Navaratnam
Berkelium was first discovered in December 1949 at the University of California at Berkeley. I chose to represent as much information of the element onto the hexagon while remaining true to the identity of berkelium. A significant feature is the presence of the logo for the University of California at Berkeley. The main features present in the regular logo are replaced by information that are true to berkelium.
Californium, 98
Thousand Oaks High School
Thousand Oaks, California, USA
Teacher: Rhonda Frohn
Artist: Madeline Biggs
Californium was first discovered at Berkeley, California in the 1950s. It is a very strong neutron source and is used to find gold and silver ores through neutron activation. The design of the element took place in fall of 2018, so the strong note on my element artwork symbolizes recent events in my community, including the Borderline shooting and local wildfires in November 2018. Our recovery is strong, and representing my strong community in an international setting is an honor.
Einsteinium, 99
Palm Beach Currumbin State High
Currumbin, Queensland, Australia
Teacher: Lee-Anne Bramley
Artist: Lily de Groot
Einsteinium, named after Albert Einstein, is a synthetic element discovered in 1952 during examination of debris of the first hydrogen bomb. Einsteinium was discovered by scientist Albert Ghiorso and his team. A mushroom cloud and radioactive hazard sign represents how it was discovered, and its radioactive properties. Albert Ghiorso has been placed in front with silhouettes to represent his team. The beach setting and ocean background represents where the bomb was tested: the Pacific Ocean. The use of glitter represents the small amount of element created, and also that it glows blue due to energy released during radioactive decay.
Fermium, 100
Aviation High School
Clayfield, Queensland, Australia
Teacher: Maureen Monteiro
Artist: Sebastian Damceski
The idea for the artwork starts first with the green tile because fermium is radioactive and radiation is commonly associated with the green colour. Secondly, since it was discovered at the Ivy Mike Test Centre where a thermonuclear device was also tested, I added a mushroom cloud to represent the dangerous process that first created fermium. Thirdly, the radioactive symbol is added to recognize fermium's radioactive property.
Mendelevium, 101
Westwood Community High School
Fort McMurray, Alberta, Canada
Teacher: Lori Simpson
Artist: Farah Sadek
Westwood pays homage to the great thinker, Mendeleev, in our design for mendelevium. He formulated the reasons science lovers are celebrating this year, an early version of the periodic table. Synthesized by crashing einsteinium with alpha particles in a particle accelerator, mendeleevium was discovered by Albert Ghiorso, Glenn T. Seaborg, Gregory Robert Choppin, Bernard G. Harvey, and Stanley G. Thompson in 1955 at the University of California, Berkeley. The design of Westwood's Chem 35 class ties all these aspects and history behind the seemingly simple element. Made by combining acrylic, watercolour, and digital techniques, we hope to honour the mysterious element and the great man it is named after.
Nobelium, 102
Hackettstown Middle School
Hackettstown, New Jersey, USA
Teacher: LisaMarie Bamber-Wichtendahl
Artist: Sarah Newen
The medium of my illustration is a colored pencil outlined with Sharpie. The illustration depicts the four discoverers of the element nobelium: Albert Ghiorso, Glenn T. Seaborg, Torbjorn Sikkeland, and Georgy Flerov. Alfred Nobel, the chemist who discovered dynamite and founded the Nobel Prize foundation, is also featured since element 102 was named after him. Behind each of the figures are the flags of their nationality. Lastly, the uppermost triangle holds the element's name, symbol, and atomic number in an original font.
Rutherfordium, 104
Lauren Hill Academy
Montreal, Quebec, Canada
Teacher: Nora Pang
Artist: Minah Shin
Rutherfordium was first discovered in Dubna, Russia, in 1964 by a team of scientists led by Georgy Flerov. It's a radioactive element and named after the scientist, Ernest Rutherford. The element was name after Rutherford to honour him because he is considered as the father of nuclear Physics and Chemistry. These characteristics inspired me to draw a portrait of Rutherford and a radiation warning symbol in the artwork. In addition, I put the electron shell configuration of rutherfordium.
Dubnium, 105
University of Toronto Schools
Toronto, Ontario, Canada
Teacher: Jennifer Howell
Artist: Janice Chung
The artwork gives credit to strategies employed by both Russian and American teams who found different isotopes of dubnium. 249Cf was bombarded by the American team with 15N, where four neutrons are emitted with a 260Db atom. The arrows make a stylistic "t", in a nod to Doctor Otto Hahn whose discoveries on Nuclear Fission made the American experiment possible. The Americium, used by the Russians, is displayed in the holding chamber of a Heavy Ion Linear Accelerator (HILAC) used to discover the element. A visual representation of fission in depicted in the HILAC chamber.
Seaborgium, 106
Clint ISD Early College Academy
Clint, Texas, USA
Teacher: Alexandra Falcon-Soriano
Artist: Chem Club Member
The artwork depicts Albert Ghiorso who co-discovered seaborgium, as well as eleven other chemical elements. Ghiorso not only spent countless hours in the lab, but he also spent days upon days researching different methods and inventing machines to help his research. His work ethic is something seen in very few people, making him an admirable and inspirational individual. Drawing him was a surreal experience because he has been such a role model in my academic life. I hope my drawing can speak for itself and for others inspired by the life of Albert Ghiorsi, a scientist unnoticed. Seaborgium was discovered in 1974 and named after Glenn T. Seaborg for his involvement in the synthesis, discovery, and investigation with transuranium elements.
Lawrencium, 103
Lawrence Park Collegiate Institute
Toronto, Ontario, Canada
Teacher: Christina Papaiconomou
Artists: Sina Tafreshi, Lucas Chua, Bianca Pedretti, Eddie Vidovic
Lawrencium was named after Ernest Lawrence, the inventor of the cyclotron particle accelerator. Through the help of the cyclotron, many radioactive elements were synthetically created by smashing particles together in a circular motion. Although lawrencium was not created using this circular particle accelerator, the element was artificially produced in a very similar fashion. This artwork of lawrencium pictures a spiral representing a cyclotron. Additionally, Ernest Lawrence is depicted to represent the origin of the element's name. Furthermore, the green and yellow colours represent the radioactivity of lawrencium, while the lackluster tone represents the relatively unknown properties of this element.
Bohrium, 107
Lytle Junior High School
Lytle, Texas, USA
Teacher: Joline Gracyn
Artist: Chessa Hartley-Mapes
Bohrium was first prepared in 1975 by Russian scientists. It was recreated in 1981 by German scientists who were credited with the discovery. I used colors representative of each country's flag in my design. Bohrium decays very rapidly, so it has no current uses. The rainbows were added to represent the short lifespan of the element since rainbows are only visible when the right conditions are present.
Meitnerium, 109
Seminole High School
Sanford, Florida, USA
Teacher: Frances Monroe
Artist: Ariana Zhai
Meitnerium is named after the scientist Lise Meitner, a pioneer for women in science. Meitner was a physics professor at Kaiser Wilhelm Institute and was one of the first scientists to discover nuclear fission, for which she shared a Nobel Prize. Because the element is named in her honor, my artwork also pays homage to her. I made this image using Adobe Illustrator, taking inspiration from black-and-white photographs and minimalist style. I took advantage of white space representing the vast amount we still have to learn about the element. Meitnerium was first synthesized in 1982 by a German research team led by Peter Armbruster and Gottfried Münzenberg at the Institute for Heavy Ion in Darmstadt.
Hassium, 108
Saint Michael Catholic High School
Niagara Falls, Ontario, Canada
Teacher: Francesca Caruso-Leitch
Artist: Anna Ly
This tile was designed by Anna Ly from Saint Michael Catholic High School in Niagara Falls, Ontario. Hassium was produced in 1984 by a team of scientists led by Peter Armbruster and Gottfried Münzenber in the Darmstadt Institute for Heavy Ion Research in Germany. This element was synthesized as a result of bombarding Pb-208 with Fe-58. Hassium was named after the German state Hesse, hence the Hesse state symbol present in the tile. Furthermore, its radioactive property is represented by the safety poster in the background.
Darmstadtium, 110
Bluevale Collegiate Institute
Waterloo, Ontario, Canada
Teacher: Maria Tuma
Artist: Laila Elhossini
On the top and bottom left, I made an illustration of common tourist sites in Darmstadt. Mathildenhöhe is depicted at the top, and the forest spiral or 'Waldspirale' is drawn in the bottom left. A particle accelerator is shown in the bottom right. These illustrations represent the city after which darmstadtium is named and the particle accelerator where it was first prepared.
Roentgenium, 111
Pui Kiu College
Hong Kong, China
Teacher: TO Chin Nang
Artists: HAU Sze Chai, Scarlett
Roentgenium was named after Wilhelm Röntgen, the discoverer of X-rays, therefore I used Röntgen with X-ray body as the main object of my design. I've added a crown with the atomic number 111 on it. The body of Röntgen merges with some chemical symbols to show its relationship with chemistry. As roentgenium is a very reactive element, different colors are used to represent its unstable property. Moreover, roentgenium properties are still unknown, like a piece of puzzle or a star in the night sky, thus I used a puzzle with a starlight color as the background.
Copernicium, 112
National Public School, Koramangala
Bangalore, Karnataka, India
Teacher: Vipina Karthic
Artists: Anvitaa Ananthkumar, Palak Pariawala
The artwork focuses on three main aspects of the element – its history, the scientists who discovered the element, and the properties it is expected to have as of now. As copernicium is a very recently developed man-made element (1996), most of the information about the element is experimental and its properties are those predicted based on its location on the periodic table. Having a very short half-life means that so far, no uses have been discovered, which is why none are mentioned in the artwork. My students created our tile using 'Inkspace' – a graphic-design tool website.
Flerovium, 114
Stanwood High School
Stanwood, Washington, USA
Teacher: Susan Hauenstein
Artist: Olivia Forcier-Capper
Flerovium (atomic number 114 and atomic mass 289) was first made in Dubna, Russia in 1998, and announced in 1999. Teams at the Joint Institute for Nuclear Research in Dubna and the Lawrence Livermore National Laboratory (LLNL) in California, led respectively by Yuri Oganessian and Ken Moody, fused plutonium-244 with calcium-48 to make flerovium. This is a synthetic radioactive element and used only in scientific studies. I made a glass mosaic using the colors red, white, and blue to represent the United States and Russian flags. I used the countries' animals to show that scientists came together to discover this element. The name Flerovium was chosen to honour Georgy Flyorov (sometimes spelled Flerov), the Russian physicist who discovered spontaneous fission.
Livermorium, 116
Livonia Churchill High School
Livonia, Michigan, USA
Teacher: Amy Lou Martin
Artist: Asenia Curka
This tile depicts the relatively new (early 2000s discovery) radioactive element Livermorium. In the artwork, there is a background sketch of the Lawrence Livermore Laboratory where several failed attempts to produce the element occurred. The lab did produce the isotopes of calcium-48 and curium-248, which were used by the Joint Institute for Nuclear Research lab in Dubna, Russia to produce the few atoms of element 116, which have been isolated. The symbol for the element contains the logo for Lawrence Livermore National Labs and a flag of both Russia and the United States.
Nihonium, 113
Tokyo Gakugei University International Secondary School
Tokyo, Japan
Teacher: Tomomi Samejima
Artist: Nanami Kuroiwa
The inspiration for the design was drawn from an interview featuring professor Morita (bottom right), the discoverer of the element. In his interview, he hinted at the importance of never giving up and believing in the project. Since this message is universal throughout all disciplines, it was appropriate to make a Senryu poem, a traditional Japanese poem, from it. (Japanese at the center; English interpretation on the bottom left.) I did this all while using the Japanese celebratory color palette of red, white, and gold, celebrating the first ever element discovered in Japan.
Tennessine, 117
Ovilla Christian School
Ovilla, Texas, USA
Teacher: Joely Glover
Artists: Audrey Nunes, Brennan Boyd
To represent tennessine, we placed a flower on the bottom left-hand corner to represent April 2010, when the element was first announced to the world. The top left has the Russian flag to recognize the contributions of the scientists in Dubna, Russia. The symbol for radioactivity represents its radioactive properties. The redwood tree with the California flag symbolizes the scientists who helped at the Lawrence Livermore National Laboratory in California. Finally, we added the Tennessee flag to the bottom right corner to give recognition to Vanderbilt University, the affiliation of the researcher who first prepared it. We also recognized the state of Tennessee, which the element is name after.
Oganesson, 118
St. Andrew's Episcopal School
Austin, Texas, USA
Teacher: Bryan Dunn
Artist: Samantha Rauch
This tile features Yuri Oganessian, the nuclear physicist after whom Oganesson is named. He has contributed to the research of transuranic elements at the Joint Institute of Nuclear Research in Dubna, Russia. Oganesson falls in group eighteen of the periodic table, and, therefore, predicted to be a noble gas. The atomic number and atomic symbol are shown as a neon light, as most colors of neon lights are produced by running an electric current through a noble gas. The tile was digitally drawn in Photoshop Creative Cloud.
Moscovium, 115
School #192
Moscow, Russian Federation
Teacher: Leonid V. Romashov
Artist: Ekaterina Belichenko
The artwork shows the main building of Lomonosov Moscow State University as a leading scientific center and a fragment of the Moscow Subway as a symbol of Moscow. Moscovium was named after the Moscow Oblast, the political subdivision where the Joint Institute for Nuclear Research is located. The laboratory was the first to prepare element 115 in 2003.