Among the elements listed below, Sulfur (S) is the one that is most likely to exhibit an expanded octet in its compounds. It is included in the exceptions in the Octet Rule. For example, SF6, the sulfur atom has 6 bonds connected to it. It has a total of 12 electrons surrounding it rather than 8 electrons only.
The average weight of an atom of an element, formerly based on the
weight of one hydrogen atom taken as a unit or on 1/16 (0.0625) the
weight of an oxygen atom, but after 1961 based on 1/12 the weight of the
carbon-12 atom.
4 Living organisms contain relatively large amounts of oxygen, carbon, hydrogen,nitrogen, and sulfur (these five elements are known as the bulk elements), along with sodium, magnesium, potassium, calcium,chlorine, and phosphorus (these six elements are known as macro minerals).
CaCO₃ is a compound in and of itself thus it is not a polyatomic ion.
Explanation:
NaCl, HCl, NaOH, KCl, CH3COOH
