Which element has the chemical symbol Si?

Silicon is represented by the chemical symbol Si on the periodic table. It is a metalloid known for its semiconductor properties and is widely used in electronics and as a material for solar cells. The designation "Si" specifically identifies silicon, distinguishing it from other elements that have different symbols.

The other options present symbols for different elements: Pb stands for lead, Hg represents mercury, and Al is the symbol for aluminum. Each of these elements has distinct properties and uses that are not related to silicon. Thus, the link between the symbol Si and the element silicon is clear and fundamental in chemistry, reinforcing the understanding of the periodic table and elemental identification.