Question

The half life of a substance is defined as the time required for the substance to decrease by half. If the weight of a substance begins at 128 grams, and the half life is 7 years, what will be the weight of the substance after 28 years?

Answer 1

the weight of the substance after 28 years is 8 grams.

How to determine the amount

We have that the half life of a substance is defined as the time required for the substance to decrease by half

The formula for calculating the half - life of a material is given as;

$N(t) = N0 (\frac{1}{2} )^\frac{t}{t^\frac{1}{2} }$

Where

• N(t) is final amount
• No is the initial amount = 128 grams
• t1/2 is the half life = 7 years
• t is the time elapsed = 28 years

Substitute into the formula

N(t) = 128 × (0. 5) ^28/ 7

N (t) = 128 × ( 0. 5) ^ 4

N(t) = 128 × 0. 0625

N(t) = 8 grams

Thus, the weight of the substance after 28 years is 8 grams.

Learn more about half life here:

brainly.com/question/26148784

#SPJ1