Hydrogen chalcogenide
A binary compound containing hydrogen and a chalcogen from group 16. Familiar examples include water, hydrogen sulfide, and hydrogen selenide.
Chalcogen: An element in group 16 of the periodic table, including oxygen, sulfur, selenium, and tellurium. The chalcogen atom defines which member of this compound family is formed.
Molecular geometry: The three-dimensional arrangement of atoms in a molecule. The bent geometry of many hydrogen chalcogenide molecules affects polarity and intermolecular attraction.
Water: The chemical compound H₂O, essential to known life and widespread on Earth. It is the most familiar hydrogen chalcogenide and a defining solvent in chemistry.
Hydrogen fluoride: The compound HF, consisting of hydrogen and fluorine, a halogen rather than a chalcogen. It resembles water in strong hydrogen bonding but belongs to a different periodic-table family.
Hydrogen: The lightest chemical element, with one proton and usually one electron per atom. Hydrogen bonds to the chalcogen in each binary compound in this family.
Electronegativity: A measure of an atom’s tendency to attract shared electrons in a chemical bond. Differences in electronegativity determine bond polarity, especially in water.
Hydrogen sulfide: The colorless, flammable, highly toxic gas H₂S, known for its characteristic rotten-egg odor. It occurs in natural gas and biological systems, and presents serious exposure hazards.
Hydrogen halide: A binary compound of hydrogen with a halogen, such as hydrogen chloride or hydrogen fluoride. Halides provide a neighboring binary-compound family for comparing acidity and bonding trends.
Group 16: The periodic-table column containing oxygen, sulfur, selenium, tellurium, polonium, and livermorium. Its elements supply the chalcogen atoms whose properties shape this family.
Acid dissociation constant: A quantitative measure of an acid’s strength in solution, expressed through its dissociation equilibrium. It compares how readily hydrogen chalcogenides release protons in water.