Ключевые слова: actinoids, atmosphere, atom, atomic, background, cadmium, cd, chemistry, compounds, design, earth, education, educational, electron, element, gases, glossy, graphic, halogens, illustration, lab, laboratory, lanthanoids, mass, mendeleev, metal, name, neutrons, numbers, periodic, physics, poster, proton, school, science, scientific, sign, solid, substance, switch, symbol, system, table, text, universe, weight,