Question

Why is $H_{2}S$ called hydrogen sulfide instead of dihydrogen sulfide?

Answer 1

Hint: A chemical formula (plural: formulas) is a means of presenting information on the chemical quantities of atoms that make up a chemical compound or molecule using chemical element symbols, numbers, and other symbols like parentheses, dashes, brackets, commas, and plus (+) and minus (-) signs.

Complete answer:
Many element symbols are taken from their Latin or Greek names rather than their current designations due to historical reasons. Both of these statements are correct. For uniformity, IUPAC has designated "sulfane" as the "parent molecule," with "hydrogen sulphide" and "dihydrogen sulphide" as valid "official" designations (actually preferred, both are "Compositional names" per IUPAC). Dihydrogen $H_{2}S$ (sulfide). Note the distinction between compositional names like ‘hydrogen peroxide' for $H_2{O}_2$ and ‘hydrogen sulphide' for $H_{2}S$ , in which the electropositive and electronegative component(s) of the term are separated by a space in English.
In the study of oxoacids, compositional names of the aforementioned kind containing the term "hydrogen" were classed as "hydrogen nomenclature". However, in order to prevent misunderstanding, they are not recommended in this context. Consider the fact that the chemical labels "hydrogen sulphide" and "hydrogen sulfide may both be read as $H_{2}S$ and $H{S}^{-}$ . The situation with $H_{2}S$ is identical to that with $N{a}_{2}S$ , which can be labelled sodium sulphide, disodium sulphide, sodium sulfide, and disodium sulfide, with the exception that mistaking the first and third designations for $NaS$ is unlikely.
To prevent misunderstanding, the terms 'hydrogen sulfide' and ‘monohydrogen sulfide' were proposed for $H{S}^{-}$ . (However, in certain languages, there is no room in compositional names, necessitating extremely fine distinctions.)

Note:
The chemical compound hydrogen sulphide has the formula $H_{2}S$ . It's a colourless chalcogen hydride gas that smells like rotting eggs. It's combustible, toxic, and corrosive. The microbial decomposition of organic waste in the absence of oxygen gas, such as in swamps and sewers, produces hydrogen sulphide; this process is known as anaerobic digestion and is carried out by sulphate-reducing bacteria.