plz ......................................help me?

if u need the atomic mass number, just memorise the atomic nos of the first 20 elements. they're in continuous order & it's really easy to memorise the atomic numbers, just write them down in order about 5 times with significant time gap in between. for the first 20 elements, most of them have atomic mass just double than that of the atomic number. and u can easily memorise the few exceptions.

this did the trick for me..........hope it helps u too.

Hmmmm???? What part of looking at the periodic table are you not getting?

The periodic table of the elements usually displays both the atomic number (the whole number) and the average atomic mass (the one with the decimal fraction).

For the molar mass (molecular weight) of a compound, simply add up the molar masses (atomic weights) of the elements that make up the compound.

I.e. The molar mass (molecular weight) of water, H2O, is 18.0 g/mol.

This comes from from 2 hydrogen atoms, 1.0 g/mol each, and 1 oxygen atom, 16.0 g/mol)

1.0 + 1.0 + 16.0 = 18.0 g/mol

The relative Atomic masses are quite often just double of there atomic numbers, or lies in the ±1 or 2 range for the low atomic mass elements..

and the questions directly asking atomic masses are usually from the elements up to atomic number 20..

which are quite easy to remember..

this general for first 20 range only..

if you go higher then the change can be greater..

Hope it helps..!!

wtf.....u dnt kno this thing.......carbons atomic wieght is 12...find out others on net..

what is your weight?