Covalent metals, such as MgB 2 and the alkali-doped fullerenes, form an unusual class of superconductors. The mechanism of superconductivity in a new member of this family — the silicon clathrates — ...

Note: This video is designed to help the teacher better understand the lesson and is NOT intended to be shown to students. It includes observations and conclusions that students are meant to make on ...

The latest short science news items from C&EN. Open an introductory chemistry textbook. What is a covalent bond? A covalent bond occurs when atoms share electrons in a molecule. What is a hydrogen ...

The distribution of outermost shell electrons, known as valence electrons, of organic molecules was observed for the first time. As the interactions between atoms are governed by the valence electrons ...

This video explains covalent bonding. A covalent bond is a shared pair of electrons. Covalent bonding forms molecules. Substances with small molecules have low melting and boiling points and do not ...

The dot and cross diagram shows that a water molecule is made up of one oxygen atom joined to two hydrogen atoms, so the formula of water is H 2 O. A nitrogen molecule is made up of two nitrogen atoms ...