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.
From 1943 to 1969, thirteen african american women earn the Ph.D. in Mathematics. 1943 Euphemia Lofton Haynes (Catholic University), the first african american woman, and Clarence F. Stephens (University of Michigan) become the ninth and tenth african americans to earn a Ph.D. in Mathematics. See our web page Black Women in Mathematics for a chronology of the first 20 Black women Ph.D.'s.