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.
The answer is; D
Carbon dioxide and methane are potent greenhouse gases. They cause heating of the lower atmosphere, by trapping sunlight, that results to climate change. Due to the higher melting and boiling temperatures of phosphorus, it is rare that it occurs as gas in room temperatures. Phosphorus, therefore, does not pose a great threat of climate change.
These are the things that convert nitrogen in the soil -cyanobacteria<span>participate. After nitrogen has been fixed, other </span>bacteria<span> convert it into </span>nitrate<span>, in a process known as nitrification.</span>
<h2>Tropomyosin</h2>
Explanation:
This protein is most likely: Tropomyosin.
Sacromere is the structural unit of myofibrils i.e. the fibres of the muscles.
Tropomyosin is the muscle protein that function in contraction of muscle filaments.They are arranged laterally along the myofilament. When the researcher is observing the sacromere, she is observing the muscle fibre. So, the protein that lines the periphery along the thin filament is more likely to be tropomysin.
An earthquake hits a small island. All but a few individuals of a lizard species are eliminated in this catastrophe, and an allele is lost from the population. This is an instance of the bottleneck effect.
Natural events like an earthquake catastrophe which eliminates, by chance, a large number of individuals of a population, can amplify the phenomenon of genetic drift. It is termed as the bottleneck effect. It leads to the elimination of a large part of the genome abruptly.
Immediately, the survivors' genetic composition becomes the whole population's genetic composition, which might be very distinct from the population that existed before the catastrophe.
To learn more about genetic drift here
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