11.   The starry furnaces in turn transformed the hydrogen and helium into a variety of heavier elements, including carbon, nitrogen, oxygen, silicon and iron.

12.   Then, working with three other scientists, Hoyle figured out how all the heavier elements could have been formed.

13.   Then, with three other scientists, Hoyle figured out how all the heavier elements could have been formed.

14.   This is how stars transmute light elements from the beginning of the universe into heavier elements, the stuff of planets, minerals and people.

15.   When such a massive star exhausts its primary fuels of hydrogen and then helium, it must consume successively heavier elements that have been produced in its fusion furnace.

16.   During fusion reactions, the nuclei of lighter chemical elements fuse to create heavier elements.

17.   Elements heavier than uranium have been produced by nuclear bombardment, in particle accelerators and in nuclear explosions during the past half-century.

18.   Heavier elements, called transuranic, are produced by atomic bombardment or in nuclear explosions.

19.   Nuclear fusion entails welding two isotopes of hydrogen together at ultra-high temperatures, causing them to form a heavier element in a burst of release energy.