The time it takes for 1g of strontium-90 to decay to 250 mg is; 57.6 years
<h3>What is the half life of an element?</h3>
The formula for half life is;
A(t) = A₀ * (¹/₂)^(t/t_1/2)
Where;
A(t) is amount left after t years
A₀ the initial quantity of the substance that will undergo decay;
t_1/2 is the half-life of the decaying quantity.
We are given;
t_1/2 = 28.8 years
A₀ = 1 g
A(t) = 250 mg = 0.25 g
Thus;
0.25 = 1 * (¹/₂)^(t/28.8)
log 0.25 = (t/28.8) log (1/2)
-0.60206 = (t/28.8) * -0.3010
t = 2 * 28.8
t = 57.6 years
Read more about half life at; brainly.com/question/11152793
I don't get it theres so much symbols
Answer:
Part A:
<u>Encoding failure</u>: This applies to the the AP exam because if the terms are not consciously read and studied, it won’t be encoded, and it won’t be remembered. This influences failure on the exam, rather than success.
<u>Predictive validity</u>: Regarding the AP exam, the test is made to predict the future behaviour of the student within the course. Therefore, if the test score is high, the retention of content in the future should be higher than that of a person with a lower test score. The same can be said for the AP course or the AP practice tests. These resources are made to predict what the test score is most likely to be, if the test has predictive validity.
<u>Distributed practice</u>: This will influence success on the AP exam because it allows for better recall rather than recognition, so writing the portion will be more successful.
<u>Proactive interference</u>: This could influence failure on the AP exam because previously learned information such as learnings from biology class or chemistry class can interfere with the newly learned information from psychology, especially since these subjects can cross content.
Part B:
<u>Procedural memory</u>: In a performance task, procedural memory comes in handy because writing letters or typing is easy without thinking about it.
<u>Acetylcholine</u>: This can lead to failure on the performance task because procedural memory might be impaired or recognition of everyday material might exacerbate the difficulty of the already challenging task.
<u>Emotional intelligence</u>: Having high emotional intelligence would influence success in the performance task because it allows for greater creativity when thinking of issues about others and when solving issues.
Explanation:
Make sure to paraphrase and put into sentences with the DDAFC structure of an FRQ:
Define
Discuss
Apply- I provided this but make sure to paraphrase for academic integrity :)
Full Circle
Answer:
20
Explanation:
You would set up a proportion in order to solve this
3 green 12 green
------------ = ------------
8 total x total
Then you would cross mulitply for x and get 32. Since that is the total number, you would have to subract the 12 from 32 to get 20.
