GENERAL KNOWLEDGE

Detailed explanation-1: -When the universe was still very young, only a few kinds of atoms existed. Scientists believe that around 100, 000 years after the big bang, helium and hydrogen combined to make a molecule called helium hydride for the first time.

Detailed explanation-2: -Light elements like hydrogen and helium formed during the big bang, and those up to iron are made by fusion in the cores of stars. Some heavier elements like gallium and bromine need something more, such as a supernova.

Detailed explanation-3: -Of these three, helium was the first to begin forming “real” atoms. An atom is more than a nucleus-it must also possess electrons. Helium nuclei were the first to gather a full purse of electrons en masse. Why not hydrogen or lithium?

Detailed explanation-4: -Light elements (namely deuterium, helium, and lithium) were produced in the first few minutes of the Big Bang, while elements heavier than helium are thought to have their origins in the interiors of stars which formed much later in the history of the Universe.