Define essential elements and how many elements are required for life

Living organisms contain relatively large amounts of oxygen, carbon, hydrogen, nitrogen, and sulfur (thesefive elements are known as the bulk elements), along with sodium, magnesium, potassium, calcium, chlorine, and phosphorus (these six elements are known as macrominerals).

1= c 2= a or d3 = idk sorry 4= c5= c

Rate law for this reaction israte of the reaction = k[a]²[b].second order in a  means concentration of a in power of two, and  first order in b means concentration of b in power of one.