Where do I find these items in B/W???

Question

kings rock, smooth bell, prisma scale, deep sea scale/tooth??

Answer 1

So the locations are pretty simple:
Kings rock:
Iccirus City, Pick up(ability), route 13, held by wild slowbro, poliwhirl, poliwrath, politoed and slowking

Soothe bell: First thing, theres no such thing as smooth bell
A lady in Nimbasa City will check your Pokemon and if good enough, will give a soothe bell

Prism scale: Not prisma.
Route 13, Undella town, and the ability pick up

Deep sea scale:
Route 13, held by wild chinchou, lanturn, relicanth and Blue striped basculin

Deep sea tooth:
Route 13 and 17 and held by wild carvanha, sharpedo and Red striped Basculin

Source: Bulbapedia

Answer 2

In Black/White;
Kings Rock - Route 13 (Treasure Hunter)
Soothe Bell - Nimbasa City
Prism Scale - Route 13 (northeastern shore) , Undella Town
DeepSeaScale - Route 13 (Treasure Hunter), Route 13 (North of some Fisherman)
DeepSeaTooth - Route 13 (Treasure Hunter) , Route 17 (NE of Swimmer Wright)

Seribii and Bulbapedia