National Institutes of Health
Ncbi: The Molecular Biology of the Cell: The Chemical Components of a Cell
Advanced chapter of the book "The Molecular Biology of the Cell" describes and provides illustrations of our most current understanding of the chemical makeup of cells and their components. Explains in detail how electron activity keeps...
BBC
Bbc: Gcse Bitesize: Covalent Bonds
A covalent bond is formed between non metal atoms, which combine together by sharing electrons. Covalent compounds have no free electrons and no ions so they don't conduct electricity.