Potassium (K) has a higher ionization energy compared to hydrogen (H). Ionization energy refers to the energy required to remove an electron from an atom or ion in the gaseous state.
The ionization energy generally increases from left to right across a period in the periodic table. This is because the effective nuclear charge, which is the positive charge experienced by the outermost electrons, increases as you move across a period. In other words, the number of protons in the nucleus increases, attracting the electrons more strongly and making it more difficult to remove an electron.
In the case of hydrogen, with its single valence electron, the ionization energy is relatively low. This is because hydrogen only has one electron, and the attractive force between the single proton in the nucleus and the electron is not as strong compared to elements with multiple protons. Therefore, it requires less energy to remove the electron from a hydrogen atom.
On the other hand, potassium has one valence electron in its outermost shell. However, potassium has a larger atomic number and more protons in its nucleus compared to hydrogen. This increased positive charge in the nucleus results in a stronger attraction for the valence electron. As a result, it takes more energy to remove the electron from a potassium atom compared to hydrogen.
In summary, potassium has a higher ionization energy than hydrogen because the increased nuclear charge in potassium, resulting from more protons, leads to a stronger attraction for the valence electron, making it more difficult to remove.