🟢 Qué es un ENLACE COVALENTE | Estructura de Lewis: Simple, doble y triple
Introduction to Covalent Bonds
Overview of the Lesson
- The video introduces a lesson on covalent bonds in chemistry, presented by Miguel Fernández Collado.
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Definition of Covalent Bonds
- A covalent bond is formed when non-metal atoms combine, sharing electrons to achieve noble gas configuration.
- Shared electrons are central to covalent bonding; Lewis diagrams illustrate this concept using element symbols and dots for valence electrons.
Types of Covalent Bonds
Simple, Double, and Triple Bonds
- In Lewis diagrams, shared electron pairs are represented by lines between atoms; for example, Cl2 forms a simple covalent bond with one shared pair.
- Oxygen (O2) forms a double bond by sharing two pairs of electrons due to its six valence electrons.
- Nitrogen (N2) creates a triple bond by sharing three pairs of electrons, making it stronger than both single and double bonds.
Representation in Lewis Structures
- Different elements can form covalent bonds; hydrogen's valence is shown as 'x' while oxygen's is depicted with a dot in H2O.
- CH4 demonstrates four single covalent bonds where carbon shares with four hydrogens.
Complex Molecules and Their Formulas
Molecular Composition
- Molecules can contain various types of covalent bonds; COCl2 has one double bond and two single bonds.
- The formula H2O2 indicates two hydrogen atoms bonded with two oxygen atoms, emphasizing molecular composition over mere proportions.
Covalent Crystals vs. Molecular Substances
Characteristics of Covalent Crystals
- Diamonds exemplify perfect crystals where each carbon atom connects to four others through strong covalent bonds; they are hard and electrical insulators.
Properties of Graphite and Silica
- Graphite consists of layers where each carbon atom binds to three others but retains an unbonded electron that allows conductivity.
- Silica (SiO2), forming a 3D network structure, results in quartz or sand which is hard and also an electrical insulator.
Properties of Covalent Substances
Summary of Physical Properties
- Covalent crystals tend to be solid at room temperature with high melting points while being hard and generally non-conductive except graphite.