Which of these elements are unlikely to form covalent bonds: \(\mathrm{S}, \mathrm{H}, \mathrm{K}, \mathrm{Ar},\) Si? Explain your choices.

First, we must identify the nonmetal elements among S, H, K, Ar, and Si. In the periodic table, nonmetals are found to the right of the metalloids and include elements such as hydrogen, oxygen, and nitrogen. In this list, S (sulfur), H (hydrogen), Ar (argon), and Si (silicon) are nonmetals. K (potassium) is a metal.

To determine which nonmetals are more likely to form covalent bonds, let's analyze their electron configurations. Nonmetals tend to form covalent bonds by completing their outer electron shell, either by sharing or gaining electrons from other nonmetals. Sulfur (S): 1s2, 2s2, 2p6, 3s2, 3p4 Hydrogen (H): 1s1 Argon (Ar): 1s2, 2s2, 2p6, 3s2, 3p6 Silicon (Si): 1s2, 2s2, 2p6, 3s2, 3p2

Now let's assess their likelihood to form covalent bonds based on their electron configurations. Sulfur (S): Sulfur has 6 valence electrons (3s2, 3p4) and needs two more electrons to complete its outer shell. It is likely to form covalent bonds. Hydrogen (H): Hydrogen has 1 valence electron (1s1) and needs one more electron to complete its outer shell. It is also likely to form covalent bonds. Argon (Ar): Argon has a full outer electron shell (1s2, 2s2, 2p6, 3s2, 3p6). Since it has a stable electron configuration, it is a noble gas and does not need to form covalent bonds. Silicon (Si): Silicon has 4 valence electrons (3s2, 3p2) and needs four more electrons to complete its outer shell. It is likely to form covalent bonds. Among the elements S, H, K, Ar, and Si, argon (Ar) is the element that is unlikely to form covalent bonds, since it has a complete outer electron shell and does not need to share/gain electrons. The other nonmetals are likely to form covalent bonds to achieve a stable electron configuration.