Welcome to the Electronic Learning Environmental (E.L.E.) for physical science and basic chemistry. Classically,chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation. This is a worksheet to provide information for testing purposes. I wish you well and earn a high grade. And thank you for using Proprofs and Mitchell's Cosmic Adventure, science website.