h2o and h2se which greater polarizability
According to the journal article that is entitled Atomic Polarizability and Electronegativity by Jeffery K. Nagle, there is a “close relationship between atomic electronegativity and polarizability”. Therefore, water (H2O) has a greater polarizability than hydrogen selenide (H2Se) because oxygen is more electronegative than selenide.
Polarizability is the measure of ease with which the electrons and nuclei can be displaced from their average positions. In other words, polarizability is the measure of the abilities of atoms or compounds to form instantaneous dipoles. Therefore, if a substance has a large polarizability, then it is inferred that the magnitude of the instantaneous dipoles of the substance is large. Thus, there would be a strong attraction amongst the particles of such a substance.
Valence electrons are the largest contributors to the polarizability of a substance because they are the electrons that are the furthest from the nucleus. Larger atoms usually demonstrate more polarizability. This is because larger atoms usually have more energy levels. Thus, the valence electrons of large atoms are shielded from the nucleus and, therefore, more likely to be displaced.
Similarly, the polarizability of a compound increases with size and the number of atoms in the molecule.