Central atom

[Kelly Zhang 1L]

For the lewis structures, how do we determine which atom is the central atom?

[RachaelKoh3A]

Generally, the central atom is the atom that has the lowest ionisation energy. Ionisation energy increases across a period and decreases down a group.

[Nikitha_lakshminarayanan3I]

It is dependent on the ionization energy, however there are some exceptions. The book lists those.

[Catherine Kim 3K]

Generally the atom with the lowest ionization energy is the central atom.

[Cameron_Greenberg_3C]

The atom with the lowest ionization energy is in the center. I usually look for which atom is furthest to the bottom left of the periodic table. If there is only a single atom bonded to multiple of a different atom, then the single atom will be central. ex: NH3 has nitrogen in the center

[Rosha Mamita 2H]

The atom that has the lowest ionization energy will be at the center, though there are exceptions. For example, hydrogen will never be a central atom