Question

write the name and structure of an aldehyde with 4 carbon atoms in its molecule

Answer 1

butanal

and the structure is :   CH3--CH3--CH3--C=O
                                                                      I
                                                                    OH

Answer 2

as there are four carbons, the prefix of the name will be" but"
as it is a aldehyde functional group, it will have suffix "al"
thus the name is" butanal"
the structure will be:
CH3-CH2-CH2- C -H
                             11
                              O
 Hope it helps!!!!!