Chemistry of the p-block

Chemistry of the p-block

Properties of p-block Elements

  • The elements in the p-block of the periodic table consist of Groups 3-0. These elements have their outermost electrons in the p-orbital.
  • The general electronic configuration of p-block elements can be represented as ns²np^1-6.
  • Across each period in the p-block, the number of valence electrons increases from 1 to 6.
  • P-block elements comprise metals, non-metals and metalloids.

Reactivity of p-block Elements

  • The reactivity of p-block elements is primarily determined by the ease of electron loss, electron gain, or covalent bonding.
  • Group 3 and 4 elements tend to form covalent bonds whereas from group 5 to 7, elements often show a tendency to form anions by gaining electrons.
  • p-block elements can display a variety of oxidation states due to the availability of valence electrons in multiple shells.

Elements of Group 5

  • Group 5 elements, also known as nitrogen group, include Nitrogen (N), Phosphorus (P), Arsenic (As), Antimony (Sb) and Bismuth (Bi).
  • These elements have five electrons in their outer shell.
  • Nitrogen forms strong triple bonds in its diatomic form.

Elements of Group 6

  • Group 6 elements, also known as the oxygen group, include Oxygen (O), Sulphur (S), Selenium (Se), Tellurium (Te) and Polonium (Po).
  • Oxygen is a strong oxidising agent due to its ability to accept electrons and its high electronegativity.
  • Sulphur can exist in different allotropic forms and display a wide variety of oxidation states.

Elements of Group 7

  • Group 7 elements, also known as the halogens, include Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I) and Astatine (At).
  • Halogens have seven electrons in their outer shell.
  • Halogens are very reactive and tend to form salts when they react with metals.
  • As you move down the halogen group, the elements become less reactive and have higher atomic radii.

Elements of Group 0

  • Group 0 elements are known as the Noble gases, including Helium (Ηe), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe) and Radon (Rn).
  • These elements have a full electron shell and are generally unreactive due to their stable electronic configuration.

Shapes of Molecules (VSEPR Theory)

  • Valence Shell Electron Pair Repulsion (VSEPR) theory can be employed to predict the shape of p-block element molecules.
  • Based on this theory, electron pairs around a central atom move as far away as possible from each other to minimise electron-electron repulsion.
  • This theory also considers the influence of lone pairs, which can affect the observed shape of the molecule.

Inter-molecular Forces in p-block Elements

  • P-block elements can participate in several types of intermolecular forces: Van der Waals forces, dipole-dipole forces, and hydrogen bonding.
  • The strength and type of intermolecular force impact the substance’s physical properties such as boiling point, solubility and volatility.

Keep these key points in mind when studying the chemistry of the p-block. Understanding the trends within the p-block and the characteristics of each group will form a solid foundation for tackling various questions on this topic.