Question

1. how can non - metal elements achieve a stable electron - shell structure like that of the noble gases?

Explanation:

Non - metal elements can achieve a stable electron - shell structure like noble gases by gaining electrons to form anions, sharing electrons through covalent bonds, or accepting a share of electrons in a coordinate covalent bond. This fills their outer electron shell to have 8 electrons (octet rule, except for hydrogen which aims for 2 electrons), similar to noble gases.

Answer:

Non - metal elements can achieve a stable electron - shell structure like noble gases by gaining electrons to form anions, sharing electrons through covalent bonds, or accepting a share of electrons in a coordinate covalent bond.