An element is a chemical substance made up of a particular kind of atom and hence cannot be broken down or transformed by a chemical reaction into a different element, though it can be transmuted into another element through a nuclear reaction.
Almost 40 years separate Shirley Ann Jackson's achievement, as the first African-American woman to earn a Ph.D. in theoretical high energy physics at Massachusetts Institute of Technology, and Jedidah Isler, the first African-American woman to receive a Ph.D. in Astrophysics from Yale.
1870: Ada Kepley became the first American woman to earn a law degree, from Northwestern University School of Law. 1870: Ellen Swallow Richards became the first American woman to earn a degree in chemistry, which she earned from Vassar College in 1870.