Aurous is a cation of gold. Gold takes the name "aurum" (Au) with atomic number of 79. In its purest form, the element is bright, slightly yellow, soft, ductile, and malleable. The charge of aurous is +1. Sulfide, on the other hand, has a charge of -2.
Hence, the chemical formula of the compound is Au₂S and its systematic name is gold (I) sulfide.
Option C: elements produce spectra with only few distinct lines.
The spectra are not continuos and are different for every element. This permits to identify elements.
Find the hydroxide ion concentration of a solution with a pOH of 5.90. To solve this, use a scientific calculator and enter 5.90 and use the +/- button to make it negative and then press the 10x key.