The atomic mass of elements on different peiodic tables.

[monokekie]

hi there,

I am wondering which periodic table should i use as reference when doing exercises to prepare myself for the exam. since some periodic tables have atomic mass to 3 decimal places, whereas some are rounded off to one decimal.

For some questions, I get different answers from the ones suggested on the heinemann book, and that makes me wonder which period table should i use.

I have already got familiar with the ones with 3 decimal places, but a lot of answers i got from using those data seems to be wrong.

Which peiodic table do you guys recommend that i use? and would i loose mark in an exam if my answer differs with the actual answer by about 0.1?


thanks in advance for your help

[Edmund]

Use the data book given by VCAA.

You will lose marks if your answers is different, you must state answer correct to a certain number of significant figures (read the question).

Post on sig fig here: http://vcenotes.com/forum/index.php/topic,3632.0.html

A data book can be found in here: http://www.vcaa.vic.edu.au/vce/studies/chemistry/chem1_sample_2008.pdf

Edit: 3 significant is given in the Periodic Table by VCAA, use that, and you won't go wrong.

[monokekie]

yeah, i have read that..

but i have another periodic table which says Sulfur is 32.065, while the one on the vcaa says it is 32.1

which one should i trust?

since the VCAA one is less accurate, and coblin says that we should "round off at the end- despite what the solution suggests"

sorry, but i am really really really confuzed...

please inform

[Edmund]

Its alright to use the one in VCAA.

If the question in the exam says:

Given that the Mplar Mass of Sulfur is 32.065, find .......

then you use 32.065

otherwise follow the periodic table given in data book.




Note: Also, if you are doing questions from the Heinemann book, you must use the periodic table behind the book in order to get the right answers....

[monokekie]

 :'(i have to rememorise all the stuff on the priodic tables?!

arhhh .. no

anyway
thanks

[shinny]

 :'(i have to rememorise all the stuff on the priodic tables?!

arhhh .. no

anyway
thanks

Whut? You're given the VCAA data book in the exam so you don't needa memorise anything. For the purposes of VCE, just always use that for any constants you need to look up to get used to where to find things in the book.

[monokekie]

i thought it would save me enormous amount of time by putting things in my head.

[shinny]

If you've done the amount of revision you're meant to do, you'll automatically remember the ones you need to anyway. Most of the numbers are pretty straight forward and I don't really know anyone who struggled to remember the common constants.