Thallium-207 decays exponentially with a half life of 4.5 minutes. if the initial amount of the isotope was 28 grams, how many grams of the isotope will remain after 7 minutes?

Option B

Step-by-step explanation:

Thallium-207 decays exponentially with a half life period = 4.5 minutes.

So the explicit formula of exponential decay can be written as

=

= Amount after decay

= initial amount

n = decay constant

t = time for decay

Since half life of Thallium is 4.5 minutes.

So   =

ln = ln

-0.69314 = -4.5n ln e

4.5 n = = 0.154

Now we have to calculate amount remaining after 7 minutes when initial amount taken is 28 grams from the formula

=

=

grams

Option B is the answer.

Answer : B. 9.53 grams

Thallium-207 decays exponentially with a half life of 4.5 minutes. if the initial amount of the isotope was 28 grams,

The formula for half life is

Final value = initial value (1/2)^(Time /t(half life))

initial amount of the isotope = 28 grams

half life = 4.5 minutes

Time = 7 minutes

Plug in all the values

Final value

A = 28 * 0.34020= 9.52553

9.53 grams of the isotope will remain after 7 minutes

answer: given that the roller coaster can accommodate 1600 riders per hour, thus the roller coaster can accomodate 1600 / 60 = 26.67 riders per minute.

given that there are 345 people in the line, the number of minutes it will take for the 345 persons to get into the roller coaster is given by 345 / 26.67 = 12.94 minutes.

therefore, it will take you 12.94 minutes to get to the front of the line.

step-by-step explanation:

the answer will be the last one