Lily replicates an experiment that found that the number of calories in a particular food is 50 kcal. she obtained data from

five trials: 50 kcal 72 kcal, 50 kcal, 12 kcal, and 50 kcal. which best desribes her data results? a. accurate b. incorrect c. invalid d. precise

Explanation:

Accuracy describes how close the experimental measure is to the correct value.

In this case the number of calories found in the experiment that is being replicated would be considered as the correct value to compare: 50 kcal.

The result of the experiment carried out by Lily is the average of the five trials:

Round to two significant figures:

Find the error:

That is not a big error, that drives to conclude that the data results are incorrect, so discard option B (incorrect) and it is, indeed, relatively accurate.

Precision measures how close the data obtained are close to each other. You can see that there is great dispersion, since the data are in the range [12, 72], which is too big compared with the average.

Thus, at once you can conclude that the data are not precise (option D. is discarded).

You cannot talk about validity since that is more related with the experimental procedure, so discard option C.(invalid).

- "the choice that is not an indicator of a chemical change is "state of matter changes". more common than not, chemical reactions produce energy in the form of light or heat. along with energy, they also produce a new substance called the product that could be in any state of matter (solid, gas, or liquid)."