Identify the name of the functional group in the following compounds:
(i) `H-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-NH_(2)`
(ii) `H-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-Br`
(iii) `H-underset(H)underset(|)overset(H)overset(|)(C)-overset(O)overset(||)(C)-H`
(iv) `H-underset(H)underset(|)overset(H)overset(|)(C)-overset(O)overset(||)(C)-underset(H)underset(|)overset(H)overset(|)(C)-H`.

Explanation

(i) `-NH_(2)("amino")`
(ii) `-Br("bromo")`
(iii) `-C-overset(O)overset(||)(C)-H`(al)
(iv) `-overset(O)overset(||)(C)-`(one)