What is stone in relation to body weight and what does a stone equal in pounds?

The compound Pb2Se4 consists of lead (Pb) and selenium (Se) elements. To determine the compound name, we use the rules for naming binary compounds.

Since lead (Pb) is a metal and selenium (Se) is a nonmetal, we use the prefix "di-" to indicate two atoms of lead (Pb) and the prefix "tetra-" to indicate four atoms of selenium (Se). The suffix "-ide" is used for the nonmetal, selenium (Se).

Therefore, the compound name for Pb2Se4 is lead(II) selenide.