dioxide

"All he had to show for four years of attendance at college was a framed piece of paper."

""The bakery sells cupcakes individually, priced at two dollars each." "

"The science teacher conducted an experiment to demonstrate how plants grow in different types of soil. "

"The pencil's lead is made of carbon. "

"We need oxygen to breathe. "

"The box containing my old toys was stored in the attic. "

"Rust is an iron oxide. "

"After the race, her chest rose and fell with each heavy exhale. "

"The chemistry class focused on how different elements combine to form new substances. "

"The box contains my old toys. "

"The air we breathe is made of tiny atoms like oxygen and nitrogen. "

"Hydrogen chloride is a diatomic molecule, consisting of a hydrogen atom and a chlorine atom."