Final answer:
The least metallic element among Si (Silicon), Ge (Germanium), As (Arsenic), and Sb (Antimony) is As (Arsenic), due to its classification as a nonmetal and its position in the periodic table.
Step-by-step explanation:
The question asks which of the following elements is least metallic: Si (Silicon), Ge (Germanium), As (Arsenic), or Sb (Antimony). To determine the metallic character, we should consider the position of the elements in the periodic table. The metallic character generally increases down a group and decreases across a period from left to right. Therefore, elements positioned closer to the bottom left corner are usually more metallic.
Among the given elements, Si (Silicon) is the most to the right and is known to be a metalloid, which makes it less metallic than Ge (Germanium) and Sb (Antimony), which are also metalloids but located a bit further to the left. As (Arsenic) is considered a nonmetal. However, comparing the metalloids and Nonmetals, nonmetals are least metallic.
Thus, the least metallic element among the given options is As (Arsenic).