Measurement Accuracy and Uncertainty Concepts

Why is there always some uncertainty in scientific measurements?

• Instrument limitations

• Human error

• Environmental factors

• Calculation errors

What must a proper measurement include?

• All of the digits that are certain

• Only the estimated digits

• Only the largest digits

• Only the smallest digits

How do the lines (graduations) on a measuring instrument relate to the precision of a measurement?

• The smaller the lines, the better the measurement

• The larger the lines, the better the measurement

• Lines only indicate whole numbers

• Lines are irrelevant to measurement quality

What is considered the "uncertain" part of a measurement when reading an instrument?

• The space between the lines

• The first digit

• The last digit

• The unit of measurement

When estimating the uncertain part of a measurement, how many decimal places should be included in the space between the lines?

• Only one decimal place

• Two decimal places

• Three decimal places

• As many decimal places as possible

What is the curved surface of a liquid in a graduated cylinder called?

• A meniscus

• A gradient

• A calibration

• A volume curve

When reading the volume of a liquid in a graduated cylinder, which part of the meniscus should be used for the measurement?

• The bottom of the curve

• The top of the curve

• The sides of the curve

• Any part of the curve

What is the correct volume reading from the graduated cylinder shown?

• 21 mL

• 21.3 mL

• 21.30 mL

• 21.300 mL

What is the correct mass reading from the triple beam balance shown?

• 163 g

• 163.7 g

• 163.70 g

• 163.700 g

If the arrow on the ruler indicates a measurement, which of the following is the most appropriate reading?

• 1.9 cm

• 1.94 cm

• 2.0 cm

• 1.945 cm