Iron
Blood - a fluid connective "tissue" - is the primary transport medium of substances, such as oxygen and nutrients, in the body.
Oxygen is responsible for rusting and combustion. Chemical formula for it is O2.
The primary element in the atmosphere is nitrogen.
Iron is the element responsible for transporting oxygen to the blood. It is a vital component of hemoglobin, the protein in red blood cells that binds to oxygen and carries it throughout the body.
Iron is itself an element, symbolized as Fe.
Primarily hemoglobin which is derived from the mineral Iron. Iron however works in conjunction with dozens of other minerals and supplementation must include as many of it's co-factors as possible.
Carbon is another element that is primary in a living organism.
No, silicone is not a primary compound of sand. Sand is mainly composed of silica, which is a compound made of silicon and oxygen. Silicones are synthetic compounds made from silicon, oxygen, and other elements like carbon and hydrogen.
The lungs absorbs oxygen into the blood
No, Oxygen is an element and Carbon is an element. Thus Oxygen and Carbon are elements.
Oxygen is the element responsible for supporting life and burning. It is essential for respiration in living organisms and is a key component in combustion reactions.
Red blood cells are a major cell component of blood responsible for carrying oxygen. They contain hemoglobin, a protein that binds to oxygen in the lungs and transports it to tissues throughout the body.