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.
Answer:
A catalyst
Explanation:
Enzymes are not a catlysy
The best answer to the question 'What are the nonliving components of the environment that shape an ecosystem?' would be letter d. Abiotic factors are those components of the environment that are non-living or does not have life. All the other choices have life.
First, there is a need to understand what the carrying capacity is as it relates to the environment:
- Carrying capacity refers to the maximum number of individuals of a particular species that and environment can support based on the resources it has.
- The population of a species in an environment grows and oscillates around the carrying capacity of the environment.
Now let us look at the graph. The population size grew from 0 and then leveled off at 2,000 with time. The leveling-off also happened without any oscillation, meaning that the maximum population size the environment can support is 2,000.
Hence, the portion on the graph that indicates the carrying capacity would be the plot where the population size is 2,000 and the time being between 12 and 18. This has been circled and labeled as 'K' in the attached image.
More about carrying capacity can be found here: brainly.com/question/20270121
<span>During the final days of her life, Celeste will likely be in more much pain, and it will be more difficult to control. She will likely not be able to move around on her own, or even speak. She will have difficulty swallowing, and may not be able to eat. Celeste will need help with basically all of her self-care, and activities of daily living.</span>