The big bang sent the basic building blocks of hydrogen, helium, and traces of lithium out into the Universe. Gravity caused this material to collapse into stars, galaxies, and clusters of galaxies. The other elements in the Universe, from which the earth and all life are made, were created in stars through the thermonuclear process. Millions of years will pass before a star begins to exhaust its nuclear fuel supply, causing it to expand into a red giant. The red giant becomes unstable, causing the inner core to collapse, creating a supernova, leaving an end-point, in this case, a neutron star, and in other more massive cases, a black hole.
Artist concept of big bang explosion creating stars, galaxies, and clusters of galaxies. Artist concept of a star expanding into a red giant, then creating a supernova, then becoming a neutron star.