Ключевые слова: 3d, analyse, analyzing, atom, atomic, cells, chemical, chemistry, concept, density, educate, education, educational, electron, element, experimentation, formula, hg, lab, laboratory, learn, learning, mass, measure, measurement, mendeleev, mercury, molecule, nuclear, periodic, physics, power, proton, quantum, research, school, science, scientific, scientist, sign, structure, study, studying, substance, symbol, system, technology, university,