Alexandra Kamusheva,<\/strong><\/p>\n Zlatina Zlatanova<\/strong><\/p>\n Sofia University<\/em><\/p>\n https:\/\/doi.org\/10.53656\/nat2025-3.01<\/a><\/p>\n Abstract.<\/strong> \u201cChemistry Festival\u201d is a student competition designed for students from 5th to 12th grade. The goal of the competition is to promote chemistry among young people and provide a platform for students interested in the natural sciences to showcase their talents. The organization of the competition involves prior registration of participant\/participants and a supervisor\/teacher; selection of a topic predefined by the organizers; and a choice of participation category: essay, poster, or presentation. The research project category is available for students in grades 8. \u2013 12., where they present their projects on a topic related to Chemistry and Environmental Protection, using the scientific method. Participants\u2019 work is evaluated based on predefined criteria, and those with the highest scores qualify for a defense in front of a jury. After hearing and assessing the participants\u2019 presentations, the jury awards first, second, and third places in each category, along with special and incentive prizes.<\/p>\n Keywords: <\/em>chemistry education; informal education; competition<\/p>\n SEE MORE<\/a><\/p>\n <\/p>\n <\/p>\n Category \"Essay<\/em>\u201c<\/em>, <\/em>5. \u2013 7. grade<\/em><\/p>\n Gincho Gichev, 7th grade<\/strong>[1]<\/a><\/p>\n Supervisor: Rositsa Stefanova<\/strong><\/p>\n \u201cHristo Botev\u201d Secondary School \u2013 Nova Zagora (Bulgaria)<\/em><\/p>\n https:\/\/doi.org\/10.53656\/nat2025-3.02<\/a><\/p>\n Abstract. <\/strong>Aluminum is a part of our lives, whether we realize it or not. Every day, we use objects that contain this metal. But behind its everyday use lies a long and fascinating history filled with scientific discovery, curiosity, and perseverance. This is what inspired me to choose aluminum as my topic: it brings together history, science, innovation, and potential for the future. In my essay, I refer to aluminum as the \u201cFatal 13\u201d, its position as the 13th element on the periodic table, is \u201cfatal\u201d in a positive sense: it shakes up science and industry, opens up new horizons, and shown us how something unknown for centuries can become an essential part of daily life. I fully support the words of Dmitri Mendeleev: \u201cThe future belongs to this metal.\u201d<\/p>\n Keywords<\/em>: metal; aluminum; experiment; recycling<\/p>\n SEE MORE<\/a><\/p>\n <\/p>\n <\/p>\n <\/p>\n Category \"Essay<\/em>\u201c<\/em>, <\/em>5. \u2013 7. grade<\/em><\/p>\n Jemal Kamberov, 6th grade<\/strong>[1]<\/a><\/p>\n Supervisor: Fatime Hussein<\/strong><\/p>\n \u201eBratia Miladinovi\u201c Municipal School \u2013 Village Konarsko, Yakoruda (Bulgaria)<\/em><\/p>\n https:\/\/doi.org\/10.53656\/nat2025-3.03<\/a><\/p>\n Abstract.<\/strong> The paper examines the role of chemistry in the production and protection of banknotes and coins \u2013 key elements of economic life. It is explained that banknotes are made of special paper containing cotton or linen fibers, and in more modern cases \u2013 from a polymer, which making them stronger and more durable. The chemical components in these materials enable the incorporation of security features such as watermarks, microprinting and metal threads. In addition, nanoparticle inks are used to create holographic and other visual anti-falsification effects. Coins are made of metals or alloys such as copper, nickel and aluminum. Their composition is chosen based on the desired properties \u2013 corrosion resistance, strength and workability. The author shares a personal experiment with an old silver coin, which is successfully cleaned with baking soda. The conclusion is that chemistry is an integral part of creating durable, secure and modern money.<\/p>\n Keywords:<\/em> chemistry; banknotes; coins; durability; falsification<\/p>\n SEE MORE<\/a><\/p>\n <\/p>\n <\/p>\n <\/p>\n Category \"Essay<\/em>\u201c<\/em>, <\/em>5. \u2013 7. grade<\/em><\/p>\n Ibrahim Misankov, 6th grade<\/strong>[1]<\/a><\/p>\n Supervisor: Fatime Hussein<\/strong><\/p>\n \u201eBratia Miladinovi\u201c Municipal School \u2013 Village Konarsko, Yakoruda (Bulgaria)<\/em><\/p>\n https:\/\/doi.org\/10.53656\/nat2025-3.04<\/a><\/p>\n Abstract.<\/strong> The paper examines the importance of chemistry in the production and protection of banknotes and coins from antiquity to the present day. It describes the historical development of money \u2013 from natural materials to gold and silver coins, and later paper and polymer banknotes. It emphasizes that modern banknotes are not made of ordinary paper, but of special materials such as linen, cotton and polypropylene, which provide both durability and protection. Complex chemical inks and elements such as iron and strontium are used. Coins are made from alloys containing copper, nickel and zinc, which are resistant to corrosion. The author also shares a personal experience with a 10-lev banknote, demonstrating its chemical characteristics. The conclusion is that chemistry is an integral part of daily life, even in objects that we often take for granted.<\/p>\n Keywords:<\/em> chemistry, banknotes, coins, gold, polymer<\/p>\n SEE MORE<\/a><\/p>\n <\/p>\n <\/p>\n <\/p>\n Category \"Essay<\/em>\u201c<\/em>, <\/em>8. \u2013 10. grade<\/em><\/p>\n Gabriela Ivanova, 10th grade<\/strong>[1]<\/a><\/p>\n Supervisor: Galya Aralova-Atanasova<\/strong><\/p>\n Vocational Secondary School of Design \u201cElisaveta Vazova\u201d <\/em>\u2013 Sofia<\/em><\/p>\n https:\/\/doi.org\/10.53656\/nat2025-3.05<\/a><\/p>\n Abstract. <\/strong>The paper examines the chemical, biochemical, microbiological and fermentation processes involved in the production of an ancient, long-forgotten drink that is becoming increasingly popular today - mead. Low-alcohol craft mead (13.5% alcohol) was prepared at home according to a traditional family recipe, from natural polyfloral honey produced by the family apiary. A logo of the family company that would produce the drink was created.<\/p>\n Keywords:<\/em> mead; making homemade mead; branding<\/p>\n SEE MORE<\/a><\/p>\n <\/p>\n <\/p>\n <\/p>\n Category \"Essay<\/em>\", 8. \u2013 10. grade<\/em><\/p>\n Ivaylo Borisov, 9th grade<\/strong>, 9. \u043a\u043b\u0430\u0441<\/strong>[1]<\/sup><\/a><\/p>\n Supervisor:<\/strong> Maya Ganeva <\/strong><\/p>\n Secondary School with Advanced Foreign Language Studies \u201cDr. Petar Beron\u201d \u2013 Pernik (Bulgaria) <\/em><\/p>\n https:\/\/doi.org\/10.53656\/nat2025-3.06<\/a><\/p>\n Abstract. <\/strong>The goal of every person is to realize themselves through the acquisition of knowledge and skills, in this sense, money is only a means to achieve goals. That is why Peter Thiel is cited at the beginning of the paper. The topic of the chemistry of banknotes and coins is interesting with the unusual connection between the familiar from daily life and the scientific processes behind them. The goal is to understand how chemical compounds are used in the creation of banknotes and how they contribute to their security, durability and aesthetic value. Information from various sources was used to describe processes such as the production of polymer banknotes, the use of security and thermochromic inks, as well as the application of fluorescent to prevent counterfeiting and fading. The results show that money is more than a means of payment: it is the product of complex chemical technology. This leads to the idea that chemistry is not just a science, but a force that shapes the world around us in an imperceptible but significant way.<\/p>\n Keywords:<\/em> chemistry; money; banknotes; protection; technology<\/p>\n SEE MORE<\/a><\/p>\n <\/p>\n <\/p>\n <\/p>\n Category \"Essay<\/em>\", 8. \u2013 10. grade<\/em><\/p>\n Maria Kirilova, 9th grade<\/strong>[1]<\/a><\/p>\n Supervisor: Ralitsa Ranchova <\/strong><\/p>\n https:\/\/doi.org\/10.53656\/nat2025-3.07<\/a><\/p>\n Abstract.<\/strong> The essay focuses on aluminum, calling it the \u201clucky\u201d 13th element, because, from its discovery to the present day, it has been linked to technological progress. Its chemical and physical properties make it important and indispensable. It is no coincidence that the author uses a quote from the father of cosmonautics, Konstantin Tsiolkovsky, as the motto of the essay. The author\u2019s dream is to explore the Universe, understand how it works, and, perhaps, discover new chemical elements or create new alloys that will help find new worlds.<\/p>\n Keywords:<\/em> aluminum; astronautics; space research<\/p>\n SEE MORE<\/a><\/p>\n <\/p>\n <\/p>\n <\/p>\n Category \"Essay<\/em>\", 8. \u2013 10. grade<\/em><\/p>\n Hristiana Hristova, 9th grade<\/strong>[1]<\/a><\/p>\n Supervisor: Maria Stoynova <\/strong><\/p>\n \u201cVasil Levski\u201d Secondary School \u2013 Sevlievo (Bulgaria)<\/em><\/p>\n https:\/\/doi.org\/10.53656\/nat2025-3.08<\/a><\/p>\n Abstract.<\/strong> The theme of the paper is about how chemistry helped Bulgaria create its first real money, because behind each coin lies more than just metal \u2013 it carries scientific thought, political will and even a bit of national pride. The essay explains how copper, silver and gold were chosen not only for their value, but also for their chemical properties \u2013 how they react, how they are preserved and what they say about the time in which they were made. The essay shown how science and in particular chemistry helped to build a stable and sustainable currency in the Principality of Bulgaria. The essay presents interesting discoveries from archives and books are shared that show how we have used foreign technologies and knowledge while building our own monetary system. This essay is a way to show that chemistry is not just formulas, but can also tell the story of a country\u2019s history.<\/p>\n Keywords:<\/em> chemistry; coins; metals; copper; silver; history; Principality of Bulgaria; scientific approach<\/p>\n SEE MORE<\/a><\/p>\n <\/p>\n <\/p>\n <\/p>\n Category \"Essay<\/em>\", 11. \u2013 12. grade<\/em><\/p>\n Zhenya Petrova, 11th grade<\/strong>[1]<\/a><\/p>\n Supervisor: Mimi Dimova<\/strong><\/p>\n \u201cSt. Kliment Ohridski\u201d Secondary School \u2013 Dobrich (Bulgaria)<\/em><\/p>\n https:\/\/doi.org\/10.53656\/nat2025-3.09<\/a><\/p>\n Abstract. <\/strong>The paper explores the chemical nature of the transformation in onion flavour during thermal processing. The aim of the study is to explain how, through chemical reactions \u2013 particularly the Maillard reaction and caramelization \u2013 onions change their pungent taste into a sweet one. The author employs a popular science approach based on literature sources and an analysis of the onion\u2019s components (sugars, amino acids, sulphur compounds, etc.). The main conclusion is that taste is the result of complex chemical interactions that give food new properties. In this context, the preparation of French onion soup becomes an example of applied chemistry, linking scientific knowledge, sensory experience, and culture tradition.<\/p>\n Keywords:<\/em> onion; carbohydrates; Maillard reaction; caramelization; taste; food chemistry<\/p>\n SEE MORE<\/a><\/p>\n <\/p>\n <\/p>\n <\/p>\n <\/p>\n Category \"Poster<\/em>\", 5. \u2013 7. grade<\/em><\/p>\n Mia Bazovska, 6th grade<\/strong>[1]<\/a><\/p>\n Supervisor: Madlena Kolcheva <\/strong><\/p>\n https:\/\/doi.org\/10.53656\/nat2025-3.10<\/a><\/p>\n Abstract.<\/strong> The poster reveals the properties and uses of a very valuable metal today \u2013 aluminum. The aim is to introduce people to this incredible metal that has been used for over 200 years, but is ideal for both modern life and the future. The first section provides information about the history of aluminum, the second discusses its use in automotive engineering, and the third focuses on its application in electric vehicles.<\/p>\n Keywords:<\/em> aluminum; properties; automotive industry; green metal<\/p>\n SEE MORE<\/a><\/p>\n <\/p>\n <\/p>\n <\/p>\n Category \"Poster<\/em>\", 5. \u2013 7. grade<\/em><\/p>\n Maria Alexandrova, 6th grade<\/strong>[1]<\/a><\/p>\n Supervisor: Rumyana Stoineva <\/strong><\/p>\n https:\/\/doi.org\/10.53656\/nat2025-3.11<\/a><\/p>\n Abstract<\/strong>. <\/strong>Money has accompanied human history since the dawn of civilizations \u2013 from bartering and cocoa beans to electronic cryptocurrencies. The first coins appeared in Lydia in the 7th century BC, marking the beginning of the classical payment model. With the growth of trade, more convenient forms of currency were needed \u2013 paper and later polymer banknotes. In modern times, with the development of technology, digital currencies and blockchain systems are gaining ground, with Bitcoin marking a new era in the history of money. Today, in the conditions of global digitalization, central banks are also developing their own digital currencies, shaping the future of the monetary landscape.<\/p>\n Keywords:<\/em> barter; money; coins; cryptocurrencies; polymer banknotes; bitcoin<\/p>\n SEE MORE<\/a><\/p>\n <\/p>\n <\/p>\n <\/p>\n Category \"Poster<\/em>\u201c<\/em>, <\/em>5. \u2013 7. grade<\/em><\/p>\n Yoan<\/strong> Hashamov, 6th grade<\/strong>[1]<\/a><\/p>\n Supervisor: Daniela Baeva<\/strong><\/p>\n \u201cYordan Yovkov\u201d Primary School \u2013 Varna (Bulgaria)<\/em><\/p>\n https:\/\/doi.org\/10.53656\/nat2025-3.12<\/a><\/p>\n Abstract.<\/strong> With the development of modern technologies and the progress in chemistry, paper banknotes have become complex financial instruments that combine art, science and security. This is necessary to prevent counterfeiting and to ensure the authenticity of the currencies. To protect the banknotes, one of the most advanced technologies, such as watermarks, security threads, holograms and optical variable inks, are used. Banknotes paper consists of special mixtures that include cotton and linen to increase durability and resistance to wear. These materials make banknotes more flexible and durable than ordinary paper. To prevent wear and extend the lifespan of the banknotes, various chemicals are added, including special polymers and protective coatings. These additives also help preserve the colors and printing on the banknotes.<\/p>\n Keywords:<\/em> banknotes; falsification; technology; ink; watermark<\/p>\n SEE MORE<\/a><\/p>\n <\/p>\n <\/p>\n <\/p>\n Category \"Poster<\/em>\", 8. \u2013 10. grade<\/em><\/p>\n Stilyan Atanasov, 10th grade<\/strong>[1]<\/a>,<\/p>\n Nikola Ivanov, 10th grade<\/strong>[1]<\/a><\/p>\n Supervisor: Galina Kirova <\/strong><\/p>\n \u201cVasil Drumev\u201d High school of Mathematics and Natural Science \u2013 Veliko Tarnovo (Bulgaria)<\/em><\/p>\nThe Fatal 13<\/h3>\n
The Chemistry of Banknotes and Coins \u2013 Progress of Science<\/h3>\n
Chemistry of Banknotes and Coins from the Time of Our Great-Grandparents to the Present<\/h3>\n
Chemistry of Mead<\/h3>\n
Chemistry of Banknotes and Coins<\/h3>\n
Aluminum \u2013 the \u2018Lucky\u2019 13th Element<\/h3>\n
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The Metal of Time<\/h3>\n
Is French Onion Soup Sweet?<\/h3>\n
Aluminum \u2013 the Lightweight Heavy in Automotive Industry<\/h3>\n
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Money \u2013 History and Necessity<\/h3>\n
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Chemistry of Paper Banknotes \u2013 US Dollar<\/h3>\n
Aluminum \u2013 from Waste to Resource<\/h3>\n