Final answer:
The nonmetal elements that combine with two hydrogen atoms to satisfy the octet rule are Oxygen (O) and Sulfur (S), both forming covalent bonds to complete their valence electron shell.
Step-by-step explanation:
To select the nonmetal elements that combine with two hydrogen atoms to satisfy the octet rule, we need to consider the number of valence electrons nonmetals possess and how many bonds they tend to form. When a nonmetal atom combines with another nonmetal atom, they usually form a covalent bond, which is a shared pair of electrons.
Hydrogen, with one valence electron, forms one covalent bond, thereby obeying the duet rule rather than the octet rule. On the other hand, elements from the second period such as oxygen (O) and fluorine (F) need to achieve a full octet in their outer shell.
Oxygen, with six valence electrons, will form two bonds with hydrogen to make H₂O (water), while fluorine, also with seven valence electrons similar to chlorine, will form one bond with hydrogen, as in HF (hydrogen fluoride). Elements like carbon (C) and nitrogen (N) also follow the octet rule by forming four and three bonds with hydrogen to make CH₄ (methane) and NH₃ (ammonia), respectively.
In conclusion, based on the octet rule and their respective electronic configurations, the nonmetal elements from the given list that can combine with two hydrogen atoms to satisfy the octet rule are Oxygen (O) and Sulfur (S).