Calculate the average atomic mass of a sample of antimony that is 57.21% antimony-121 (120.938 amu) and 47.79% antimony-123 (122.904 amu).

chemistry sucks a**

explanation:

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.

every chemical equation adheres to the law of conservation of mass, which states that matter cannot be created or destroyed. therefore, there must be the same number of atoms of each element on each side of a chemical equation.