An example of a non-metal with a high ionization energy is helium (He). Ionization energy refers to the amount of energy required to remove an electron from an atom or ion in the gaseous state. Helium is a noble gas and is known for its extremely high ionization energy.
Helium has a filled electron shell with two electrons, and it follows the octet rule, meaning it is stable with its current electron configuration. Consequently, removing an electron from helium requires a significant amount of energy. The first ionization energy of helium is exceptionally high, and it is the highest among all the elements on the periodic table.
The high ionization energy of helium is a result of its small atomic size and the strong electrostatic attraction between the positively charged nucleus and the two electrons in the 1s orbital. These factors make it difficult to remove an electron from helium, thus giving it a high ionization energy.
It's worth noting that other non-metals such as neon (Ne), argon (Ar), and other noble gases also have high ionization energies due to their stable electron configurations and the strong attraction between the nucleus and electrons.