Question

A nucleophile is the species that should have
A.A pair of electrons to donate
B.A positive charge
C.A negative charge
D.Electron deficient species

Answer 1

Hint: A nucleophile contains an electron pair available for bonding i.e. it is electron rich. It is a molecule that forms a bond with electrophile by donating electrons for the bond. Since it is an electron donor so it possesses a negative (-) charge.

Complete step by step answer:
The word ‘nucleophile’ has two parts, namely nucleus and philos. ‘Philos’ is the Greek word for ‘love’. Therefore, nucleophiles are Nucleus Loving species. Nucleophile is an atom or molecule that seeks a centre position such as the nucleus of an atom in a chemical reaction. A nucleophile contains a pair of electrons available for bonding that bonds to an atom other than Hydrogen.
A nucleophile is an electron loving species that donates the electron pair to an electrophile. And due to this electron donating tendency of the nucleophile, they are all Lewis bases.
Thus, it is an electron donor and possesses a negative (-) charge.
Examples of Nucleophiles: Negatively charged species carrying negative charge donates the lone pair like Hydroxide ions $(O{H^ - })$ , Halogen ions $(C{l^ - },{l^ - },B{r^ - })$ , Cyanide ion $(C{N^ - })$

So, the correct answer is option (A) and (C).

Note: The nucleophilic nature of a species describes that the species are attracted to the positively charged nucleus. The nucleophilicity trends are: the nucleophilicity increases as the charge on the atom becomes more negative within the group in the periodic table. The nucleophilicity increases with the basicity (higher electron density). It also increases with polarizability (size) as it enhances the ability to form the new C-X bond within the group in the periodic table.