Each of five students used the same ruler to measure the length of the same pencil. These data resulted: 15.33 cm, 15.34 cm, 15.33 cm, 15.33 cm, 15.34 cm. The actual length of the pencil was 15.85 cm. Describe whether accuracy and precision are each good or poor for these measurements.

Precision is good but accuracy is poor

Explanation:

The precision in a measure is about how close is a measured value to each other. In the problem, all measurements are between 15.33 and 15.34cm. Thus, you can say precision is good

And accuracy is about how close are the measured values to the theoretical or real value. The real length of the pencil is 15.85cm. The measurements are not even close of the real value. For that reason, you can sat accuracy of the measurements is poor.

a:

by the combination of an unlimited number of elements

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.