Under most conditions, an atom of one of the noble gases is
inert because their outer orbital contains the maximum number of electrons; the completion of their outer orbital makes these elements more stable and less able to react with other atoms and molecules.A) because their outer orbital contains the maximum number of electrons; the completion of their outer orbital makes these elements more stable and less able to react with other atoms and molecules.
B) because its outer orbital contains the maximum number of electrons; the completion of the outer orbital makes the atoms of the elements more stable and less able to react with other atoms and molecules.
C) because its outer orbital contains the maximum number of electrons, which makes these elements more stable and less able to react with other atoms and molecules.
D) because their outer orbital contains the maximum number of electrons, making these elements more stable and less able to react with other atoms and molecules.
E) because their outer orbital contains the maximum number of electrons, and the completion of their outer orbitals makes these elements more stable and less able to react with other atoms and molecules.
The subject of this sentence is atom, a singular noun, and the rest of the sentence is about the atom of a noble gas. Therefore the pronouns referring to atom should be in the singular form as well. Yet, it is possible that the pronoun preceding outer could refer to the plural noun gases, except for the fact that the noun orbital is in the singular form. Since the noble gases do not all share a single orbital, the pronoun should be its in order to refer to atom
A) Since the noble gases do not all share a single orbital, the pronoun should be its in order to refer to the singular noun atom.
B) This sentence is correct as is. The sentence correctly places the singular pronoun its with the singular noun orbital, and there are no misplaced modifiers.
C) The participial phrase beginning with which makes, incorrectly modifies electrons. The electrons in general do not make the atom stable; the fact that the atom's outer orbital has a complete set of electrons makes the atom stable.
D) Since the noble gases do not all share a single orbital, the pronoun should be its in order to refer to the singular noun atom. The participial phrase beginning with making, incorrectly modifies electrons. The electrons in general do not make the atom stable; the fact that the atom's outer orbital has the complete set of electrons makes the atom stable.
E) Since the noble gases do not all share a single orbital, the pronoun should be its in order to refer to the singular noun atom.