 ## GOB Chemistry

Learn the toughest concepts covered in your GOB - General, Organic, and Biological Chemistry class with step-by-step video tutorials and practice problems.

Matter and Measurements

# Significant Figures: Precision in Measurements

Significant Figures are used to discuss the level of precision in any measurement.

Recording Measurements
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concept

## Significant Figures Precision Concept 1m
Play a video:
so we know that significant figures will play a role in the way we analyze data, analyze questions. We also know what's gonna have an impact on the answers that we have at the end. Now there is levels of precision that are involved when it comes to significant figures. We're gonna say here the more significant figures in a measurement than the more precise it ISS. So, for example, are reading of 25.0 Emmaus is more precise than just 25. That's because 25 00 m. Els it has a decimal point. We moved from left to right. Our first non zero number here is to count all the way to the end. This has four Sig Figs 25 on the other hand, had has no decimal point. So we moved from right to left and it on. Lee has to sick fix. Since 25.0 MLS has more significant figures. It's mawr precise. It gives us more detail now when it comes to recording measurements, significant figures have to be taken into account. So we're gonna say when taking a measurement, you must include all of the known numbers, plus an additional decimal place. Now we use what I call the eyeball test. It's based on an estimate or best guess from looking. So even when looking at a measuring tape or looking at a beaker, significant figures have to be taken into account. We can't just look at the measurements or the hash marks on these tools and say that is my value because there's some level of uncertainty there. So you have tow, add an additional decimal place toe, ensure you have the correct number of significant figures. Now that we've talked about this idea of precision and measurements, click on the next video and let's put it to practice with an example question.
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example

## Significant Figures Precision Example 1m
Play a video:
Alright everyone. So here it says in this example, question determine the number of significant figures involved in measuring the length of the square. So in measuring the length of the square, we have this measurement, we see that this here is the 3.0 centimeter hash mark, And this is 3.1 and this is 3.2. So we see 3.2 cm. Remember, with the right number of significant figures, we have to add an additional decimal place. That would mean that the best answer would be 3.20 cm. Making options see our best choice.
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Problem

Read the length of the metal bar to the correct number of significant figures. 4
Problem

What is the correct reading for the liquid in the burette provided below?  