Both the acetamido (-nhcoch3) and bromo (-br) substituents are ortho, para directors. even though the acetamido group is much larger than the bromo group, the -cl is still introduced next to the acetamido group in spite of the greater steric hinderance at this site. why?

Explanation has been given below

Explanation:

Attachment of -Cl group at ortho position to acetamido group can be explained in terms of hydrogen bonding formation.A hydrogen bonding can be formed between proton attached with N atom in acetamido group and Cl atom at ortho position. This leads to a formation of a stable 5-membered ring structure.Hence ortho substitution by Cl is favorable process.There is no hydrogen bonding possible between Br and Cl atom in ortho position. Therefore Cl prefers para position to avoid steric hindrance.Structure of hydrogen bonded structure has been shown below.

Atomicity occurs to prevent updates of the database occurring only partially, which can cause greater problems than rejecting the whole series outright.some are monatomic, diatomic, triatomic etc because it shows the number of atoms. for example, monatomic means it contains only one atom.