Final answer:
Among the elements C (carbon), Si (silicon), Ge (germanium), Sn (tin), and Pb (lead), carbon has the highest first ionization energy because of its position on the periodic table, being furthest right and highest up in its group.
Step-by-step explanation:
The question asks which of the elements C (carbon), Si (silicon), Ge (germanium), Sn (tin), or Pb (lead) has the highest first ionization energy. First ionization energy generally increases across a period (left to right) and decreases down a group (top to bottom) on the periodic table. Therefore, the element with the highest first ionization energy among the given elements is carbon (C) because it is the furthest to the right and highest up in its group on the periodic table.