Q. Living beings are made of inorganic and organic substances. According to the molecular complexity how can each of those substances be classified?

Inorganic substances, molecular oxygen, mineral salts, like water, and carbon dioxide, are small molecules made of few atoms. Organic substances, in general, fatty acids like, glucose and proteins, are much more complex molecules made of sequences of carbons bound in carbon chains. The capacity of carbon to form chains is one of the major chemical facts that permitted the emergence of life on the planet.