Final answer:
Shielding of electrons reduces the attractive forces between the nucleus and the outermost electrons in an atom, makes losing these outermost electrons easier, and thus facilitates the formation of cations.
Step-by-step explanation:
The shielding of electrons refers to the effect in which the inner (core) electrons in an atom shield or screen the outer (valence) electrons from the positive pull of the nucleus. This makes it easier for the valence electrons to get lost and hence, facilitate the formation of a cation.
When the outermost electron in an atom is shielded from the pull of the nucleus, it takes less energy to remove this electron, thereby facilitating the cation formation. For example, sodium (Na), which has a single electron in its outermost shell, can easily lose this electron to form a cation (Na+) because the shielding effect of the inner electrons reduced the attractive forces between the nucleus and the outermost electron.
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