The gain of oxygen atoms is known as? The loss of hydrogen atom by an element is known as? Oxidation and reduction is the? In the rusting of iron, the iron is? A process that involves the loss of electrons by an element is known as? The gain of electrons by a substance is known as? When an element loses electron, it forms? Who believed first that everything was made up of elements? In which century, John Dalton proposed his atomic theory? John Dalton theory brought a great progress in the subject of? Empedocles was a ___ philosopher? Who thought elements the building blocks of all materials? The term element was coined by?