The correct option is (B): \(Gd^{2+}\)
| LIST I | LIST II | ||
|---|---|---|---|
| A | Lyman | I | Near IR |
| B | Balmer | II | Far IR |
| C | Paschen | III | Visible |
| D | p-fund | IV | UV |



SN1 reaction mechanism takes place by following three steps –
The SN2 reaction mechanism involves the nucleophilic substitution reaction of the leaving group (which generally consists of halide groups or other electron-withdrawing groups) with a nucleophile in a given organic compound.
The mechanism of an electrophilic aromatic substitution reaction contains three main components which are:
The electrophilic substitution reaction mechanism is composed of three steps, which will be discussed more below.