# data[].attributes.body
Gold is not a necessary trace element for living things and neither are any of the other third row d-block elements.

# data[].attributes.body
Copper is essential for all life, but only in small quantities. It is the key component of redox enzymes and of haemocyanin.

Copper is sometimes found as the free element and is present in many minerals. Important deposits are located in Canada, Chile, Germany, Italy, Peru, U.S.A., Zambia, and Zaire. The most important copper ores are the oxides, sulphides, and carbonates. One major ore, chalcopyrite (copper pyrite), CuFeS₂accounts for about 50% of all deposits.

# data[].attributes.body
Chlorine as chloride (Cl⁻) is essential for mammals and plants. Digestive juices in the stomache contain hydrochloric acid.

Chlorine is never found in nature as the free gas. It is found mainly as rock salt (common salt, halite, NaCl), carnallite (KMgCl₃.6H₂O), and sylvite (KCl).

# data[].attributes.body
Calcium is essential for all life. It forms part of cell walls and bones. It is important for blood clotting.

Calcium metal is never found as the free metal in nature. Calcium is fifth in abundance in the earth's crust, of which it forms more than 3%. It occurs as limestone (CaCO₃), gypsum (CaSO₄.2H₂O), and fluorite (CaF₂). Apatite is calcium fluorophosphate or chlorophosphate.

# data[].attributes.body
Carbon is key to life and by definition is present in all organic compounds. The study of life is known as biological chemistry or biochemistry. Ethene gas (C₂H₄) helps to ripen tomatoes.

Carbon is found free in nature in three allotropic forms: amorphous, graphite, and diamond. Graphite is one of the softest known materials while diamond is one of the hardest. Carbon, as microscopic diamonds, is found in some meteorites. Natural diamonds are found in kimberlite of ancient volcanic "pipes" such as found in South Africa. Diamonds are also recovered from the ocean floor off the Cape of Good Hope.

# data[].attributes.body
Oxygen atoms are present in water (H₂O) and water is essential to all life. Oxygen and is present in many organic compounds. Most organisms use oxygen for respiration. While oxygen (O₂) is necessary for life, oxygen as ozone (O₃) is highly toxic. On the other hand, ozone is an important component of the atmosphere (the ozone layer) and helps to shield us from harmful ultraviolet rays from the sun.

# data[].attributes.body
Hydrogen makes up two of the three atoms in water and water is absolutely essential to life. Hydrogen is present in all organic compounds. A form of water in which both hydrogen atoms are replaced by deuterium (²H, or D) is called "heavy water" (D₂O) and is toxic to mammals. Some bacteria are known to metabolise molecular hydrogen (H₂).

# data[].attributes.body
Nitrogen is a key component of biological molecules such as proteins (which are made from amino acids, and nucleic acids. The nitrogen cycle in nature is very important.

# data[].attributes.body
Boron is probably not required in the diet of humans but it might be a necessary "ultratrace" element. Boron is required by green algae and higher plants.

# data[].attributes.body
Aluminium may be involved in the action of enzymes such a succinic dehydrogenase and δ-aminolevulinate dehydrase (involved in porphyrin synthesis. Aluminium compounds are toxic to most plants and somewhat toxic to mammals. Aluminium has been linked to Alzheimer's disease (senile dementia).