Chemistry: Types of Bonds

Types of Bonds

• Chemical bonds are forces that hold atoms together in molecules or compounds.
• Bonds can be classified into Ionic and Covalent bonds.

Ionic Bonds

• Formed by the electrostatic attraction between oppositely charged ions (cation and anion).
• Involves the transfer of electrons from metals (cation) to nonmetals (anion).
• Ionic bonds are extremely strong compared to covalent bonds.
• Occurs as a result of opposite charges attracting each other.

Covalent Bonds

• Created by the sharing of electrons between nonmetal atoms.
• Typically result in a neutral overall charge due to equal electron sharing.
• Weaker than ionic bonds; electrons are usually shared in pairs.
• Can be further classified into:
  • Nonpolar Covalent Bonds: No difference in electronegativity.
  • Polar Covalent Bonds: A difference in electronegativity exists.

Electronegativity

• Defined as the ability of an atom to attract bonding electrons.
• Greater electronegativity difference leads to increased ionic character; results in more polar bonds.
• Polar bonds generally have shorter, stronger bonds while nonpolar bonds are longer and weaker.

Ionic Bonding

• Main-group elements tend to lose or gain electrons to achieve an electron configuration isoelectronic with noble gases.
• Metals (elements following noble gases) have low electronegativities and tend to lose electrons, forming positive cations.
• Nonmetals (elements preceding noble gases) have high electronegativities, gaining electrons to form negative anions.
• The electron configuration of elements plays a significant role in the formation of ions and ionic bonds.

Electron Dot Symbol and Octet Rule

• Electron dot symbols illustrate valence electrons around an element's symbol, distributed around four sides, pairing as needed.
• The Octet Rule states that atoms tend to achieve an electron configuration with eight valence electrons, similar to that of noble gases.