20 in the formula no3, what does the subscript 3 mean?

Amniocentesis is a process in which amniotic fluid is taken from the mother's womb to identify any genetic abnormalities in the fetus. how would the discovery of the human genome contribute to this process?

Which is a genetic engineering advancement directly related to a career in biotechnology? 1) improving solar energy collection 2) transporting textiles at higher rates 3)creating crop foods that resist insect pests 4)repairing historical sites with quality materials

Identify two examples of chemical reactions that you have encountered during the last week. identify an exothermic and endothermic reaction. explain.