Properties of compounds depend on the type of bond that is formed between the atoms. Some elements are eager to achieve stability by transferring electrons either to or from another element. This type of substance consists of ionic bonds and is an ionic substance. Compounds formed between nonmetals usually share electrons to achieve a stable octet. Bonds which consist of sharing electrons are called covalent bonds and the substance is called a molecular substance. The smallest particle of a molecular substance is called a molecule. There is one more type of bonding that occurs between metals. Metals contain mobile or free roaming valence electrons. This property allows metallic compounds to be malleable, ductile and conduct heat and electricity quite well.