A nucleophilic attack occurs when a nucleophile, a species with a high electron density, approaches and reacts with an electrophile, which is electron-deficient. This interaction typically involves the nucleophile donating a pair of electrons to form a new bond, often resulting in the transformation of molecules in chemical reactions. In organic chemistry, nucleophilic attacks are crucial for processes like substitution reactions and addition reactions. Common nucleophiles include hydroxide ions and ammonia, while typical electrophiles include carbonyl compounds and alkyl halides. Understanding these interactions helps in predicting reaction outcomes and designing new chemical syntheses.