Half-life: The <u>time</u> required for a quantity to reduce to <u>half of its initial value</u>.
To find the time it takes (in days) for the substance to reduce to half of its initial value, substitute the given values into the formula and set N to half of the initial mass, then solve for t:
Therefore, the substance's half-life is 5.5 days (nearest tenth).
Learn more about solving exponential equations here: