<h2>Answer:</h2>
Family of Synthetic Elements
<h2>Explanation:</h2>
In chemical Sciences a synthetic element is a chemical element that does not occur naturally on Earth, and it can only be created artificially in the laboratory. So far, 24 synthetic elements have been created in the laboratory and their atomic numbers lie from 95–118.
Tretinoin is a naturally occurring metabolite of retinol in the retinoid class, including natural and synthetic analogues. It is the acid form of vitamin AIt acts on cell growth and differentiation. Its main use is the treatment against acne thanks to its keratolytic and anti-inflammatory properties. Tretinoin is also used in the treatment of acute myeloid leukaemia type 3 (AML 3).
SIDE EFFECTS:
Among the expected effects, side effects may occur. Signs of an allergic reaction include: hives, difficulty breathing, swelling of the face, lips, tongue or throat;
It should be known that tretinoin can make you more sensitive to the sun, so use sunscreen every day, and wear protective clothing outdoors.
Cholesterol and triglycerides should be done before and during treatment because this drug could increase their values
Some patient with leukaemia treated by tretinoin has suffered from The syndrome of retinoic acid which is characterized by fever, dyspnea, acute respiratory distress...
This is false. There are elements that have three letters, however they don't occur as often as those with one or two letter formulas.
