<span>The correct answer for this question is A - Scientists ask testable questions and devise ways in which they can answer those questions through experimentation or observation. The rest of the possible answers for this question only describe some scientists.</span>
Answer:
Explanation:
We are asked to find how much of a 40 gram sample remains after 12 years.
Iron-55 has a half-life of 3 years. Therefore, after 12 years, 4 half-lives have been completed.
- 12 years/3 years = 4 half-lives
Every time a half-life is completed, half of the sample's mass decays. Remember we start with a 40 gram sample.
- 1 half- life: 40 g / 2 = 20 g
- 2 half-lives: 20 g / 2= 10 g
- 3 half-lives: 10 g / 2 = 5 g
- 4 half-lives: 5 g / 2 = 2.5 g
There is also a formula that can be used to solve this problem.
Where A₀ is the initial amount, t is the time, and hl is the half-life.
We know 40 grams is the inital amount, 12 years is the time, and 3 years is the halflife.
After 12 years, <u>2.5 grams </u> of Iron-55 will remain.
Hey pizzalover! The answer from this question would be
a. oxygen
Hope it helps
I'm pretty sure it's answer D. It's the only answer choice that really makes sense.
<span>The "stress hormones" that were released by Benita's adrenal glands would likely be epinephrine and norepinephrine. Some studies have shown that something as simple as laughter can lower the level of stress hormones in most people. Since severe stress can lead to other health problems, it is important to get help from a medical professional to bring your stress level under control.</span>