The value which is being measured in the columns labeled "Fraction remaining" and "Percentage remaining" is: D. amount of material that has not decayed.

<h3>What is a radioactive decay?</h3>

A radioactive decay can be defined as a radioactive process in which an unstable atomic nucleus undergoes a spontaneous transformation into one or more different atomic nuclei and simultaneously emits radiation, accompanied with a loss of energy.

<h3>The types of radioactive decay.</h3>

In Science, there are three main types of radioactive decay and these include the following:

Alpha decay
Beta decay
Gamma decay

Based on the information provided in the table (see attachment), we can reasonably infer and logically deduce that the value which is being measured in the columns labeled "Fraction remaining" and "Percentage remaining" is the amount of material that has not decayed.

Read more on radioactive decay here: brainly.com/question/23303931

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