Why is the bond between two single hydrogen atoms stable?
A. It is not stable, each hydrogen only has 1 electron and they need 8 electrons to be stable.
B. Each hydrogen has 4 electrons to share for a total of 8 when 2 hydrogens bond.
C. Hydrogen only uses the first energy shell, which holds 2 electrons, not 8.
D. Each hydrogen donates more electrons in their lower energy shells to get to 8 but only to other hydrogen atoms.
The correct answer and explanation is:
The correct answer is C. Hydrogen only uses the first energy shell, which holds 2 electrons, not 8.
Hydrogen atoms are stable when they achieve a full outer electron shell, but they only require 2 electrons to fill their first and only energy shell. The hydrogen atom has a single electron in its outermost shell. When two hydrogen atoms bond, each shares its single electron with the other, forming a covalent bond. In this bond, each hydrogen atom effectively “gains” one electron from the other, filling its outer shell with 2 electrons, which is the maximum capacity for the first energy level.
This stability is different from elements like oxygen or carbon, which require 8 electrons in their outer shells (octet rule) to be stable. For hydrogen, the goal is to achieve 2 electrons in the first shell, which is sufficient for stability. This is why two hydrogen atoms can form a stable H₂ molecule, where each hydrogen atom is surrounded by 2 electrons, completing its first energy shell.
Hydrogen does not need 8 electrons in its outer shell to be stable, unlike larger atoms that follow the octet rule. Therefore, hydrogen’s stability comes from sharing electrons to complete its first energy shell rather than requiring the 8 electrons typically needed for stability in other elements. The sharing of electrons between hydrogen atoms to form H₂ is a key example of covalent bonding, where atoms achieve stability by fulfilling their electron shell requirements.