Ionic, Covalent, and Metallic Bonds
Watch this lecture to learn about the details of ionic, covalent, and metallic bonds, and how to balance chemical equations.
A compound is a substance made up of two or more different kinds of atoms. This is the fundamental distinction between an element and a compound. Rather than simply being a mixture of two or more kinds of atoms, compounds are formed when different kinds of atoms interact. This interaction gives the compound properties that differ from the properties of the constituent elements. For example, sodium chloride (table salt) is made up of the elements sodium and chlorine, but sodium chloride (the compound) is different from both of these elements. The interactions between atoms in a compound are called chemical bonds.
There are three major categories of chemical bonds:
- Ionic bonds form when one or more electron from one atom is transferred to another atom, creating a positive ion and a negative ion that are attracted to each other because of their opposite charges.
- Covalent bonds form when one or more pairs of electrons are shared by two different atoms, holding the two atoms together more strongly than an ionic bond.
- Metallic bonds consist of a "sea" of electrons that move about from one metallic atom to another, holding together many metallic atoms.
Molecules are particles that are bigger than atoms. They are made up of multiple atoms (of either the same or different elements) held together by covalent bonds. A molecule of water, for example, consists of an oxygen atom covalently (and separately) bonded to two hydrogen atoms.
Be sure you understand the distinction between atoms, ions, molecules, elements, and compounds.
Source: Khan Academy, https://youtu.be/cBygUVuiK8o
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.