Basic Scientific Concepts

Front

What is the difference between precision and accuracy?

Back

Precision tells you how close two measurements are to one another, while accuracy tells you how close a measurement is to the known value.

Front

Can a measurement be precise but not accurate?

Back

Yes, a measurement can be precise but not accurate. Precision and accuracy are not the same.

Front

What analogy is used to explain precision and accuracy?

Back

A game of darts is used as an analogy. A player who always hits the same spot just to the left of the dart board is precise but not accurate. A player who hits the all over the place, but if the average were calculated to be at the center is accurate but not precise.

Front

Why are significant figures important in scientific measurements?

Back

Significant figures are important because they help quantify the accuracy of measurements, as values in scientific measurements are never 100% accurate.

Front

What defines significant figures in a measurement?

Back

Significant figures are all the digits known with certainty and the first uncertain, or estimated, digit. It is the last digit reported in a measurement.

Front

Do zeros always count as significant figures?

Back

Zeros may or may not be significant figures. They are used to place significant figures in their correct positions.

Front

How many significant figures in the number 0.0105?

Back

The number 0.0105 has 3 significant figures. The leading zeros are not significant.

Front

What are exact numbers?

Back

Exact numbers are not measured by scientific instruments. They are used as definitions or made by counting, like the number of eggs in a carton or 100 cm in 1 m.

Front

Do exact numbers affect the number of significant figures in calculations?

Back

No, exact numbers do not affect the number of significant figures in calculations made with measured values.

Front

How do you determine the number of significant figures in a calculated result?

Back

When multiplying or dividing, the result should have the same number of significant figures as the measurement with the fewest significant figures. When adding or subtracting, the result should have the same number of decimal places as the measurement with the fewest decimal places.