Chapter 3 Lesson 1: Using & Expressing Measurements

Question 1

How do you write numbers in

scientific notation?

Answer 1

In scientific notation, the coefficient is
always a number greater than or equal to
one and less than ten. The exponent is an
integer.

A positive exponent indicates how many
times the coefficient must be multiplied by
10.

A negative exponent indicates how many
times the coefficient must be divided by 10.

Question 2

Measurement

Answer 2

a quantity that has both a number and a unit.

Question 3

scientific notation

Answer 3

a given number is written as the product of two numbers: a coefficient and 10 raised to a power.

Question 4

How do you evaluate accuracy and

precision?

Answer 4

To evaluate the accuracy of a measurement, the measured value must be compared to the correct value. To evaluate the precision of a measurement, you must compare the values of two or more repeated measurements.

Question 5

Accuracy

Answer 5

a measure of how close a
measurement comes to the actual or true
value of whatever is measured.

Question 6

Precision

Answer 6

a measure of how close a series of measurements are to one another, regardless of the actual value.

Question 7

Accepted value

Answer 7

which is the correct value for the measurement based on reliable references

Question 8

experimental value

Answer 8

the value measured in the lab

Question 9

Error

Answer 9

The difference between the experimental
value and the accepted value

Error can be positive or negative, depending on whether the experimental value is greater than or less than the
accepted value.

Error = experimental value – accepted value

Question 10

percent error

Answer 10

a measurement is the absolute value of the error divided by the accepted value, multiplied by 100%.
error
Percent error = ———————— x 100%
accepted value

Question 11

significant figures

Answer 11

a measurement include all of the digits that are known, plus a last digit that is estimated.