Which of the following Group 1 elements has the highest ionization energy?
Answer Details
Ionization energy is the energy required to remove an electron from an atom. The higher the ionization energy, the more difficult it is to remove an electron. As we move down Group 1 of the periodic table, the atomic radius increases, and the outermost electron is farther away from the positively charged nucleus. As a result, the ionization energy decreases. Therefore, the element with the smallest atomic radius in Group 1, which is Li, will have the highest ionization energy. Therefore, the answer is: 3Li.