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

x + y = 90 5x – 10y = 90 90 – 10y = 5x 90 + 10y = 5x

step-by-step explanation:

last month maria hiked the 5-mile mountain trail a number of times and she hiked the 10-mile canal trail several times. let x represent the number of times she hiked the 5-mile trail, and let y represent the number of times she hiked the 10-mile trail. if she hiked a total of 90 miles, which equation can be used to find the number of times maria hiked each trail? x + y = 90 5x – 10y = 90 90 – 10y = 5x 90 + 10y = 5x

definitely a. the others have almost all data points on one side of the line.

step-by-step explanation: