Describe how electrons are shared in covalent bonding.
Draw diagrams to illustrate covalent bonding in hydrogen, chlorine, and hydrogen chloride.
Key Concepts
Covalent Bonding: Occurs when non-metal atoms bond together by sharing electrons.
Ionic Bonding: Involves transfer of electrons from metals to non-metals, forming ions.
Stable Electronic Structure: Achieved by having a full outer energy level, similar to noble gases.
Detailed Breakdown
Hydrogen Molecule (Hâ‚‚)
Formula: Hâ‚‚ indicates two hydrogen atoms bonded.
Hydrogen Atom:
Has one electron.
Requires one more electron to fill its outer energy level (maximum of two electrons).
Covalent Bond Formation:
Two hydrogen atoms share a pair of electrons.
Both achieve a full outer energy level (two electrons), similar to noble gases.
This is represented by an energy level diagram, dot and cross diagram, and stick diagram.
Chlorine Molecule (Clâ‚‚)
Chlorine Atom:
Found in group 7 of the periodic table.
Has seven electrons in its outer energy level.
Requires one more electron to fill the outer energy level.
Covalent Bond Formation:
Two chlorine atoms share a pair of electrons to complete their outer shells.
Represented with energy level diagrams, dot and cross diagrams, and stick diagrams.
Hydrogen Chloride (HCl)
Components:
Hydrogen (H) and Chlorine (Cl) are both non-metals.
Covalent Bond Formation:
Hydrogen shares its one electron with chlorine, while chlorine shares one of its seven outer electrons.
Both achieve full outer energy levels through the shared electron pair.
Representations include energy level diagrams, dot and cross diagrams, and stick diagrams.
Diagrams
Energy Level Diagrams: Show overlapping outer energy levels with shared electrons.
Dot and Cross Diagrams: Highlight the shared electrons specifically in the outer energy level.
Stick Diagrams: Simplified representation using a line to denote the shared pair of electrons.
Additional Resources
Questions and practice exercises available in the revision workbook linked in the lecture.
Summary
Covalent bonds involve the sharing of electron pairs between non-metal atoms leading to stable electronic configurations. Understanding of these concepts is crucial for representing molecular structures in chemistry.