Answer in both chemical equations and write the names and elements and compounds involved in it. $Ag + {H_2}S \to ?$ .

Hint: In chemistry, compounds react to form new products but they do so in specific proportions. When the reactant’s proportions are different, the formation of products also differs. There are many laws that govern the reaction and the proportions in which these compounds react and thus form a proportionate reaction.

Complete step by step answer:
Chemical reactions represent the chemical changes that happen in various elements. The chemical reaction is written to represent the way and proportions that the elements and compounds adopt for the formation of products.
Only if these chemical reactions are balanced, one can represent the correct proportions in which they react.
The reaction is balanced by adding the coefficient in which the reactants form and the products form. These coefficients represent the molar coefficient and the respective number of particles that take part in a particular reaction. The quantitative study for the representation of proportions of the reactants required and the products formed is known as stoichiometry. Using this concept we can determine the number of reactants that are needed for the preparation of the specific amount of product.
The above reaction can be balanced in the following manner to satisfy the molar coefficients of the compounds.
$2Ag + {H_2}S \to A{g_2}S + {H_2}$
Here the reaction that happened can also be written as
Silver and hydrogen sulphide react to form silver sulphide with the evolution of hydrogen gas.
This is an example of a displacement reaction.

Note: The amount of substance present in a compound may be represented in various ways like the mole percentage, molarity, molality, mole fraction, etc.
There are various laws that given the coefficient of the chemical reactions like the law of multiple proportions, Gay Lussac’s law of gaseous volumes, etc.