Notes on Atomic Stability and Bonding

Stability of Atoms and Molecular Interactions

• Stability Concepts

  • Reference to two states of system based on distance:

  • Far Away: High energy state where interactions are weak.

  • Close: Lower energy state leading to different interactions.

  • Interaction potentials are discussed:

  • Unstable: Systems that do not favor stable configurations.

  • Stable: Favorable configurations that result in lower energy states.

• Helium Behavior:

  • Helium Characteristics:

  • Does not form traditional bonds; electrons do not exhibit the propensity to bond due to their arrangement.

  • Exists in a state where it can only form London Dispersion Forces (LDFs) due to weak interactions.

  • These forces are very weak and contribute to low stability.

  • Reference to an energy well indicative of ionic stability is described as weak, suggesting minimal stability.

• Hydrogen Bonding:

  • Discussion of Covalent Bond Formation:

  • When two hydrogen atoms approach each other, they share electrons.

  • This interaction is termed a Covalent Bond.

  • Covalent bonds provide significantly higher stability than non-bonding states, as the atoms are sharing a pair of electrons which leads to a stable configuration.

• Comparison of Stability:

  • The bonding of hydrogen leads to a dramatic increase in stability compared to lone atoms.

  • Stability Values:

    • Single hydrogen atoms (non-bonded): approximately 400 kJ/mol of energy associated with their weak interactions;

    • Covalent bonded hydrogen: approximately 5 kJ/mol of energy associated with the stability of the molecule.

  • Concludes significant stability difference when atoms form covalent bonds versus weak interactions.

Summary

Overall, the discussion illustrates the contrasting levels of stability between individual atoms and bonded states, emphasizing the role of electron sharing in the formation of stronger covalent bonds and the implications for molecular stability.