🧪 Tipos de Enlaces Químicos. Iónico, Covalente y Metálico
Types of Chemical Bonds Explained
Introduction to Chemical Bonds
- The video introduces the concept of chemical bonds, defining them as the union of two atoms (either identical or different) that aim for stability.
- An example provided is table salt (sodium chloride), which is stable when bonded but reactive when separated.
Stability and Electron Configuration
- According to Lewis's theory, atoms achieve stability by having eight electrons in their valence shell, with exceptions for hydrogen and helium.
- Atoms must bond with others to complete their outer electron shell, leading to three types of chemical bonds: ionic, covalent, and metallic.
Ionic Bonds
- An ionic bond occurs between a metal and a non-metal when the difference in electronegativity exceeds 1.7; one atom donates an electron while the other accepts it.
- Using sodium chloride as an example: sodium has one valence electron while chlorine has seven; chlorine takes an electron from sodium due to its higher electronegativity.
Covalent Bonds
Types of Covalent Bonds
- Covalent bonds form between two non-metals where electrons are shared rather than transferred.
- There are three types of covalent bonds: non-polar, polar, and coordinate. The video focuses on non-polar and polar covalent bonds.
Non-polar Covalent Bonds
- A non-polar covalent bond occurs between two identical atoms (e.g., molecular hydrogen), resulting in equal sharing of electrons.
- Examples include nitrogen, oxygen, fluorine, chlorine, bromine, and iodine molecules where no atom donates its electrons; they share equally.
Polar Covalent Bonds
- A polar covalent bond forms between two different non-metals where the difference in electronegativity is greater than zero but less than 1.7.
- Water is cited as an example; oxygen attracts electrons from hydrogen due to its higher electronegativity resulting in stable configurations for both elements.
Metallic Bonds
- In metallic bonding, metal atoms are closely packed together allowing their nuclei to interact within a "sea" or cloud of delocalized electrons.
- This unique arrangement contributes to properties such as electrical conductivity and malleability found in metals.