Electrophile Vs. Nucleophile

[Angelica Nava-1E]

How can I determine if an atom is an electrophile or nucleophile if it is not obvious?

[Shirley_Zhang 3O]

I suppose when you say "it is not obvious," you mean that the elements do not have obvious partial charges that are used to classify them as nucleophile or electrophile. In this case, you would need to look at the elements' likelihood of accepting or donating electrons. If the element accept electrons, then it is electrophile. If it donates electrons, it is nucleophile.

[Janice Kim 3I]

Just look at whether there are electron deficiency or electron surplus. Molecules/Elements that have many electrons are most likely negatively charged (Nucleophiles). Electrophiles are electron deficient and are attracted to positive charges. The "obvious" comes from whether the molecule/element you are looking at has more electrons that can be given away or has less electrons and is thus attracted to a positive charge.

[Ryan Cerny 3I]

Do lewis acids ALWAYS correspond to electrophiles, and lewis bases with nucleophiles? Is it that clear cut and determinable?