Some substances are extended structures, made up of billions of tightly packed atoms or molecules. Which of the following are extended structures?

As a part of an experiment a student burns propane to produce carbon dioxide and water she remembers that she must follow the law conservation of matter when writing a balanced chemical equation which of these equation adheres to the law of conservation of matter

Balance this equation co2(g) + h2o (g) show that the balanced equation obeys the law if conversation of mass

What is the maximum number of electrons that an atomic orbital can contain?