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### Sig Figs

Posted: Wed Apr 11, 2018 3:48 pm
I noticed in the empirical formula problems in in the post module assignment, some of the elements are rounded off. For example Hydrogen (instead of 1.008, it is stated as 1.0), Oxygen (instead of 15.999, it is used as 16), do we stick to this concept where we round the numbers and not put the exact same numbers? Does it matter?

### Re: Sig Figs

Posted: Wed Apr 11, 2018 5:25 pm
We should use the numbers given on the periodic table so that we can get a more accurate answer.

### Re: Sig Figs

Posted: Wed Apr 11, 2018 5:58 pm
I'm pretty sure the periodic table is used 99% of the time, you would only really use 1 for hydrogen if you did not have/were not allowed to use a calculator.

### Re: Sig Figs

Posted: Wed Apr 11, 2018 9:08 pm
Whether you choose to round or not you should still end up with an answer relatively close to what is correct. I do not think it matters all too much.

### Re: Sig Figs

Posted: Thu Apr 12, 2018 10:17 am
When we get into the part of class when sig figs matter always use the exact number on the periodic table as it gives the most accurate and precise answer!

### Re: Sig Figs

Posted: Thu Apr 12, 2018 11:42 am
Also, this may come in handy when we start using them more, but it was mentioned in class how the final answer should have the least amount of significant figures. If one part of the problem has 3 sig figs and the other part has 6 sig figs, then I think your final answer should be rounded to 3 sig figs.

### Re: Sig Figs

Posted: Thu Apr 12, 2018 4:39 pm
In case of calculations that require the usage of values from the periodic table, are we supposed to use the exact value stated or should we round it up?

### Re: Sig Figs

Posted: Fri Apr 13, 2018 12:44 pm
I believe that rounding up is correct as long as it is consistent. If the answer is relatively close I don't think there would be a problem.

### Re: Sig Figs

Posted: Sun Apr 15, 2018 8:42 pm
NabilaNizam-1K wrote:In case of calculations that require the usage of values from the periodic table, are we supposed to use the exact value stated or should we round it up?

I believe that for calculations that require the usage of values from the periodic table, we should use the exact value stated for the element in order to obtain the most accurate answer. Then, we should round up the answer to the correct significant figure according to the information given in the problem.

### Re: Sig Figs

Posted: Sun Apr 15, 2018 10:49 pm
You should typically have/use an updated and accurate periodic table.