EVERYDAY SCIENCE

Detailed explanation-1: -When the universe began, researchers believe, it was made up of gas containing light elements-mostly hydrogen and helium. The first stars formed from this material, some 300 million years after the big bang.

Detailed explanation-2: -The early universe (left) was too hot for electrons to remain bound to atoms. The first elements-hydrogen and helium-couldn’t form until the universe had cooled enough to allow their nuclei to capture electrons (right), about 380, 000 years after the Big Bang.

Detailed explanation-3: -Scientists have inferred that helium hydride was this first, primordial molecule. Once cooling began, hydrogen atoms could interact with helium hydride, leading to the creation of molecular hydrogen-the molecule primarily responsible for the formation of the first stars.

Detailed explanation-4: -At that time, the Universe was made out of about 92% hydrogen atoms and 8% helium atoms by number (or about 75-76% hydrogen and 24-25% helium by mass), with trace amounts of lithium and beryllium, but not much else.