Covalent compounds are formed only by the interactions of non-metal atoms. The number of atoms which make up covalent molecules is determined by the number of electrons in outer levels and the Octet Rule. The simplest covalent molecule is the diatomic hydrogen molecule. The Lewis Symbols are shown on the right. Home > Animations: Here are some flash animations produced for my own teaching and free for you to download and use as you wish. Jul 02, 2010 · Element symbols are either one capital letter or one capital letter followed by a lower case letter. For example, using H for hydrogen or He for helium. When counting atoms of each element in a chemical formula, first we need to identify which atoms are present. Next, we look for subscripts. The subscript affects only the atom that if follows. Like the copper atoms, each of the iron atoms that dissolves leaves two electrons behind. So you've got positively charged iron ions floating in your vinegar with the positively charged copper ions. Originally, the steel nail was neutrally charged-but when the iron ions left their electrons behind, the nail then became neg-atively charged.