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Year XXX, Issue 5, 2021<<Archive>>

Еxpеrimеnts

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COATING METALS WITH ZINC AND METHOD FOR MEASURING THE THICKNESS OF THE LAYER

When a copper coin is immersed with zinc into a solution of a zinc salt (\(\mathrm{ZnSO}_{4}, \mathrm{ZnCl}_{2}\), etc.) an electrochemical reaction occurs in the mixture. As a result, a thin layer of zinc appears on the surface of the copper which gives the i...

zinc layer; electroplating and electroless plating; redox reactions; Reactivity series of metals

From thе Rеsеаrch Lаborаtoriеs

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POTENTIAL APPLICATIONS OF ANTIBACTERIAL COMPOUNDS IN EDIBLE COATING AS FISH PRESERVATIVE

Fish is a product that breaks down quickly due to biochemical reactions that cause a decrease in the quality of its nutritional and sensory values. Natural preservatives make fish safer for consumption than fish preserved with formalin. Edible coating is a pre...

edible coating; antibacterial; preservative

Curriculum Маttеrs

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MOLECULAR MODEL AND ITS SIMPLIFICATION IN TEACHING STEREOISOMERISM AT UNDERGRADUATE LEVEL

The role of molecular models in teaching chemistry is well-known. It is widely used in explaining the shape of molecules. Several authors have reported the difficulty in teaching stereochemistry/chirality. Some researchers have pleaded that the students fac...

chemistry-teaching/learning; molecular-models; conformation; configuration; chirality

Nеw Approаchеs

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METEORS. BASIC CONCEPTS AND TERMINOLOGY

This article discusses some basic concepts related to meteor astronomy, as well as the use of the correct terminology when working in Bulgarian. Due to the huge volume of topics, this is the first part of an upcoming series that examines only the most general...

meteor; fireball; bolide; meteor phenomena; meteorites; radiant; meteor shower; meteor storm; meteoroids; meteor astronomy
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FROM THE FORMATION OF THE EARTH TO THE ESTABLISHMENT OF LUKA

The article discusses successive stages in the evolution of life up to the establishment of the prokaryotic cell emphasizing the transitions from pre-biotic environment to organic precursors, pre-RNA-RNA, RNA-proteins-DNA, DNALUCA. They are paired with the dev...

pre-biotic environment; polymerization; evolutionary transitions; bioenergetic processes; redox potential.

History & Philosophy of Sciеncе

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1300 YEARS SINCE THE BIRTH OF GEBER – BEGINNING AND FOUNDATION OF ARABIC ALCHEMY

Geber (Latinized name of Jabir ibn Hayyan (c. 721 – c. 815)) is among the most notable representatives of medieval chemistry. The article, dedicated to the 1300th anniversary of his birth, tries to depict his work as the beginning and groundwork for Arabic alc...

history of chemistry; medieval chemistry; arabic alchemy
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