Accuracy and Precision

A student measured the mass of a piece of marble and recorded the results in the table below.

The actual value of the mass of the marble is 35.0 g.

With respect to accuracy and precision, the above results are ___________.

• accurate and precise

• accurate and imprecise

• inaccurate and precise

• inaccurate and imprecise

A student measured the mass of a piece of marble and recorded the results in the table below.

The actual value of the mass of the marble is 35.0 g.

The above results exhibit a _______________ error, because all the values are _______________ than the correct value.

• systematic , higher

• systematic , lower

• random , higher

• random , lower

Two students used a digital balance to measure the mass of a solid sample.

Each student performed three trials as shown in the table below.

**The actual mass of the solid sample is 6.25g.

Which student was accurate?

• Student 1

• Student 2

• Both students (both are accurate)

• Neither student (no one was accurate)

Two students used a digital balance to measure the mass of a solid sample.

Each student performed three trials as shown in the table below.

**The actual mass of the solid sample is 6.25g.

Which students data showed HIGH precision

• Student 1

• Student 2

• Both students (both are precise)

• Neither student (no one was precise)

The mass of a 3.45-g piece of aluminum was measured several times.

The measured masses were 2.67 g, 2.59 g, 2.60 g, and 2.64g.

Use these results to explain the difference between accuracy and precision.

• high accuracy and high precision

• high accuracy and low precision

• low accuracy and high precision

• low accuracy and low precision

A student uses his thermometer and finds the boiling point of substance X to be 95°C.

He looks in a reference book and finds that the actual boiling point of this substance is 100°C.

Calculate his experimental error

• 95⁰C

• 100^0C

• -5^OC

• 5^OC

Four students measured the mass of a 5.43 g block of metal three times.

Which student had the greatest precision and greatest accuracy?

• Student W

• Student X

• Student Y

• Student Z

Four students measured the mass of a 5.43 g block of metal three times.

Which students data shows a systematic error?

• Student W

• Student X

• Student Y

• Student Z

Four students measured the mass of a 5.43 g block of metal three times.

Which students data shows a random error?

• Student W

• Student z

• Student X and Y

Four students measured the mass of a 5.43 g block of metal three times.

Which student had the greatest precision but worst accuracy?

• Student W

• Student X

• Student Y

• Student Z