26. Which of the following atoms has the largest second ionization energy?1 pointSilicon, SiCalcium, CaChlorine, ClIron, FeSodium, Na

The second ionization energy refers to the energy required to remove a second electron from an atom after one has already been removed.

The second ionization energy is always greater than the first because after losing one electron, the atom becomes a positively charged ion and the remaining electrons are attracted more strongly to the nucleus.

The atom with the largest second ionization energy among Silicon (Si), Calcium (Ca), Chlorine (Cl), Iron (Fe), and Sodium (Na) would be Chlorine (Cl).

Here's why:

1. Silicon (Si) has 14 electrons. The second ionization energy would involve removing an electron from the 3p orbital.

2. Calcium (Ca) has 20 electrons. The second ionization energy would involve removing an electron from the 4s orbital.

3. Chlorine (Cl) has 17 electrons. The second ionization energy would involve removing an electron from the 2p orbital, which is closer to the nucleus and thus more strongly attracted.

4. Iron (Fe) has 26 electrons. The second ionization energy would involve removing an electron from the 3d orbital.

5. Sodium (Na) has 11 electrons. The second ionization energy would involve removing an electron from the 2s orbital.

The electron in Chlorine's 2p orbital is closer to the nucleus and thus more strongly attracted than the electrons in the other atoms' corresponding orbitals. Therefore, it would require the most energy to remove, making Chlorine the atom with the largest second ionization energy among these options.