Complete the exercises below. Write the Lewis structure for each of the following species, describe its geometry, and indicate the oxidation state of the nitrogen: a. HNO₂, b. N₃⁻, c. N₂H₅⁺, d. NO₃⁻.

Lewis structures are diagrams that represent the bonding between atoms in a molecule and the lone pairs of electrons that may exist. They help visualize the arrangement of electrons and the connectivity of atoms, which is essential for predicting molecular geometry and reactivity. Understanding how to draw Lewis structures involves knowing the total number of valence electrons and how they are distributed among the atoms.

Molecular geometry refers to the three-dimensional arrangement of atoms within a molecule. It is determined by the number of bonding pairs and lone pairs of electrons around the central atom, which influences the shape of the molecule. Common geometries include linear, trigonal planar, tetrahedral, and octahedral, and they can be predicted using the VSEPR (Valence Shell Electron Pair Repulsion) theory.

Oxidation states (or oxidation numbers) indicate the degree of oxidation of an atom in a compound, reflecting the number of electrons lost or gained. They are crucial for understanding redox reactions and the reactivity of different species. The oxidation state of nitrogen can vary widely, and determining it involves analyzing the bonding and electron distribution in the molecule, often using rules such as the charge of the overall species and the known oxidation states of other elements.