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.
Graduate education in America advanced when Yale awarded the first doctor of philosophy degrees in America in 1861. In 1876 New Haven native Edward Bouchet received the degree of Doctor of Philosophy from Yale, the first doctorate awarded to an African American by an American university.