1 Consider the first atom of each part of the molecule. An atom with higher atomic number has higher priority. (e.g. I > Cl > C > H)  If the first atom of two groups is the same, consider the second atom(s) in the same way as the first. (e.g. -C(CH3)3 > -CH(CH3)2 > -CH2CH3 > -CH3).
1 You can also use a toilet plunger on your bathroom sink. 2  Fill up the sink with water first, the use the plunger vigorously on the drain just as you would a toilet. 3  This will lift and agitate any blockage in the drain. It will smell a bit like vinegar for about a day. 2  You can also use a toilet plunger on your bathroom sink. 3  Fill up the sink with water first, the use the plunger vigorously on the drain just as you would a toilet.
Put enough water in the bathtub or sink to cover the bottom of the plunger, block the overflow outlet with a rag, put the plunger over the drain, and push down and up five or six times. The pressure should clear any clog and open up the pipe. Lift up the plunger and the water should quickly drain away.