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.
Mae Jemison is the first black female astronaut under the NASA space program and the first black woman to travel in space when she went into orbit aboard the Space Shuttle Endeavour in 1992. She was followed by astronaut Stephanie Wilson, while Joan Higginbotham was the third black woman to venture into space.