Metals and non-metals in the periodic table

Area of Science:

• Chemistry
• Physics
• Materials Science

Background:

• The classification of elements as metals or non-metals is fundamental to chemistry.
• The periodic table's p-block visually separates these two categories.
• Early quantum-mechanical and pre-quantum approaches addressed this elemental dichotomy.

Purpose of the Study:

• To explore the reasons behind the metallic or non-metallic nature of chemical elements.
• To review the application of the Goldhammer-Herzfeld criterion to elemental states.
• To connect the Goldhammer-Herzfeld theory with Mott's work on metal-non-metal transitions.

Main Methods:

• Reviewing historical theories, including Goldhammer-Herzfeld (1913) and Hund (1934).
• Applying the Goldhammer-Herzfeld criterion to understand elemental metallization.
• Highlighting the connection between Goldhammer-Herzfeld theory and Nevill Mott's research.

Main Results:

• The Goldhammer-Herzfeld criterion, initially proposed in 1913, effectively rationalizes elemental metallization.
• The theory, after a long dormancy, has been successfully applied to predict and understand metal-non-metal transitions.
• Converging evidence from Goldhammer-Herzfeld and Mott criteria supports a universal principle for elemental classification.

Conclusions:

• The Goldhammer-Herzfeld and Mott criteria provide a simple, effective means to determine if an element is metallic or non-metallic.
• These criteria help rationalize the distinct regions of metals and non-metals in the periodic table.
• The study briefly touches upon the complexities of metallic and non-metallic states in oxides.