Answer: The ionization energy trend on the periodic table is highest to the right and upper corner
Step-by-step explanation:
Ionization energy in the periodic table tends to increase from bottom to top within a group and from left to right across a period. This trend can be understood in the context of atomic structure and electron configurations.
From top to bottom within a group, the principal quantum number (n) increases, signifying that orbitals are being added which are on average further from the nucleus. With the outermost electrons being further away, their attraction to the nucleus decreases, making them easier to remove. This situation correlates with lower ionization energy, due to the increased distance reducing the energy required to ionize the atom.
From left to right across a period, the number of protons in the nucleus increases while the number of electrons in the inner, lower-energy shells remains constant. This leads to a rise in the effective nuclear charge experienced by the valence electrons - the combined effect of the protons in the nucleus and the charges on the inner, core electrons. As a result, valence electrons are held more tightly, causing the atom to decrease in size (as reflected in the atomic radius). Consequently, removing these electrons becomes more challenging, and the ionization energy increases.
Therefore the ionization energy tends to be highest towards the upper right corner of the periodic table with some exceptions depending on the electron configurations.