Chemical Bonding Types

Chemical Bonding

Ionic Bonds

• Formed between two atoms with a large difference in electronegativity (>1.7)
• One atom loses an electron(s) to become a cation, while the other atom gains an electron(s) to become an anion
• Electrostatic attraction between the oppositely charged ions holds them together
• Typically forms between a metal and a nonmetal
• Example: NaCl (sodium chloride), CaO (calcium oxide)

Covalent Bonds

• Formed between two atoms with a similar electronegativity (<1.7)
• Atoms share one or more pairs of electrons to form a bond
• Can be polar or nonpolar, depending on the difference in electronegativity
• Can be single, double, or triple bonds, depending on the number of shared electron pairs
• Typically forms between two nonmetals
• Example: H2 (hydrogen), O2 (oxygen), CO2 (carbon dioxide)

Lewis Structures

• A way to represent the valence electrons of an atom and the bonds it forms
• Uses dots to represent electrons and lines to represent bonds
• Octet rule: atoms tend to gain, lose, or share electrons to achieve a full outer energy level of 8 electrons
• Can be used to predict the shape of a molecule and the type of bonds it forms

Electron Configuration

• The arrangement of electrons in an atom's energy levels
• Energy levels are divided into subshells, which are further divided into orbitals
• Aufbau principle: electrons occupy the lowest available energy level
• Pauli's exclusion principle: no two electrons in an atom can have the same set of quantum numbers
• Electron configuration determines the chemical properties of an element

Periodic Table

Periodic Trends

• The periodic table is arranged in a way that elements with similar properties and electron configurations are placed in the same group
• Periodic trends occur due to the change in electron configuration and atomic size across a period or group
• Trends include:
  • Atomic radius: decreases from left to right across a period, increases from top to bottom within a group
  • Electronegativity: increases from left to right across a period, decreases from top to bottom within a group
  • Ionization energy: increases from left to right across a period, decreases from top to bottom within a group
  • Reactivity: increases from left to right across a period, decreases from top to bottom within a group

Chemical Bonding

Ionic Bonds

• Ionic bonds form when two atoms have a large electronegativity difference (>1.7)
• A cation forms when one atom loses an electron(s), and an anion forms when the other atom gains an electron(s)
• Electrostatic attraction between the oppositely charged ions holds them together
• Typically forms between a metal and a nonmetal
• Examples of ionic compounds include NaCl (sodium chloride) and CaO (calcium oxide)

Covalent Bonds

• Covalent bonds form when two atoms have similar electronegativities
• More information to be added...