copper
Nitrate is a polyatomic ion, not a standalone element, and it is composed of nitrogen, oxygen, and hydrogen atoms. Nitrate is not a metal or a nonmetal, but it is considered an anion in most chemical reactions.
A new element is most likely metal because it gives people the most boners
This element is iron.
Cesium is the most alkaline element on earth.
Sodium is a highly reactivated element. It shows +1 generally when combined.
Iron is the most solid element in the Earth's core.
If by vital you mean most reactive, then the metal francium, Fr, is the most reactive element.
nonmetals
The most abundant metal in the Earth's crust is iron. The most abundant element in the Earth's core is oxygen.
Sodium (Na) is the element that would most likely form an ionic compound with fluorine (F). Sodium readily gives up an electron to fluorine to achieve a stable electron configuration, forming sodium fluoride (NaF) which is an ionic compound.
Oxygen (although hydrogen is the most abundant element in the universe)
aluminum that's aluminum for the brits aluminum is the most abundant metal in the earth's crust, it is never found free in nature. All of the earth's aluminum has combined with other elements to form compounds. Two of the most common compounds are alum, such as potassium aluminum sulfate and aluminum oxide About 8.2% of the earth's crust is composed of aluminum."