Periodic Table

[aaronharouni]

When using the periodic table how do you know where to round off?

[AvaGordon_4F]

Hi! So I had the same question and my TA (Anton) said that whenever doing calculations using molar masses, it's best to uses the entire number, including all of the decimals listed. He said it's because depending on what calculations you're doing, it may impact your final answer, and you'll never be punished for being too accurate. Hope that helps!

[Sabrina Ryu 3L]

I also heard that you should use the full number given to you on the periodic table. During lecture, Lavelle also said that you shouldn't round until the very end, so you should use the full values that you calculate whether it be grams, moles, etc.

[Saima Salam 3J]

As the replies above me have already stated, it is safer to use the entire molar mass given in the periodic table. However, every periodic table differs in the molar mass they provide on the chart. If you have a periodic table that gives the molar mass to 5 decimal places as opposed to one that gives it to 3 decimal places, the answer will not be very different from each other. It might only differ in the thousandth place or so forth.