Radioactive substances are unstable and convert over time to more stable substances. The half-life of a radioactive substance is defined as the time it takes for the substance to decay into a more stable form so that only half the original radioactive substance remains.

Here, we are given that initially...

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Radioactive substances are unstable and convert over time to more stable substances. The half-life of a radioactive substance is defined as the time it takes for the substance to decay into a more stable form so that only half the original radioactive substance remains.

Here, we are given that initially there was 7200 grams of the radioactive substance and after 16 days 900 grams was left.

7200/900 = 8 = 2^3

As only one eighth of the substance remains after 16 days, this shows that the substance has been through 3 half-lives in 16 days.

**Therefore the half life of the substance is 16/3 days.**