The half-life of Iodine-131 is approximately 8 days. Find the amount of Iodine-131 left from a 42 gram sample after 16 days. 1) 0.0006 grams

2) 21 grams

3) 10.5 grams

4) 34 grams

Step-by-step explanation:

The formula for this is

where

N is the amount of the element left after a certain amount of time (for us it is measured in days),

N₀ is the initial amount of the element in grams,

t is the number of days gone by, and

H is the half life of the element. Filling in:

which simplifies a bit to

and a bit more to

N = 42(.25) which gives us a remaining amount of

N = 10.5

a. -0.3 > -0.33

you would have to sell 24 bracelets.

step-by-step explanation:

84/3.5 = 24