_______ are substances that cannot be separated into simpler substances.

_______ represents the element hydrogen.

Molecules formed from smaller particles are called

H₂ is

A non - metal which is a good conductor of heat and electricity is

Sodium and potassium are

The symbolic representation of a compound is called its

_________ are malleable and ductile.

Noble gases have _________ molecules.

Elements and Compounds are ______ substances.