Ключевые слова: atom, background, blackboard, board, calculation, calculus, chalkboard, class, classroom, college, data, diagram, education, energy, expansion, experiment, force, formula, graph, gravity, information, lab, laboratory, law, magnet, mass, molecule, momentum, motion, newton, nuclear, number, physics, prism, problem, pyramid, quantum, research, school, science, scientific, sign, sketch chalk, study, symbol, test, theory, university,