Chemical Forums

Chemistry Forums for Students => High School Chemistry Forum => Topic started by: ght67 on August 31, 2013, 05:55:32 PM

Title: Sig figs when displaying uncertainty???
Post by: ght67 on August 31, 2013, 05:55:32 PM

If I know that a balance gives an uncertainty of +- 0.005g, how many significant figures would I need to report on a reading when the counterweights lie exactly on the 8g mark?

Some websites say to have the reading match the uncertainty's decimal places, so it would be 8.000g +- 0.005g. But other websites say to match the uncertainty's number of sig figs, so it would be 8 +- 0.005g. Which should it be?

Title: Re: Sig figs when displaying uncertainty???
Post by: Archer on September 01, 2013, 03:00:58 AM

8.000g ± 0.005 is the correct way to display uncertainty.

Title: Re: Sig figs when displaying uncertainty???
Post by: Vidya on September 01, 2013, 10:51:25 AM

your answer should be reported to three decimal places with ±0.005 (uncertainity)