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:
While asexual reproduction only involves one organism, sexual reproduction requires both a male and a female. Some plants and unicellular organisms reproduce asexually. Most mammals and fish use sexual reproduction. Some organisms like corals and komodo dragons can reproduce either sexually or asexually.
Explanation:
Population density is the aspect of population ecology of the black-tailed prairie dog does this statement describe.
Explanation:
Population density is the number of organisms are there in per unit area. It is used to measure geographical area occupied by organisms and its statistics.
In population ecology the structure, dynamics and contribution of population of species is studied. The idea of species distribution is studied in it.
The population density determines the number of species or members of particular population are present is a particular area.
An area of low density population will have more resources and more area per organism and less competition for resources and vice versa for high density population.
Prairie dogs have 12 adults per hectare of area this tells the population density of the rodents.
The time period being referred to is the sensitive period. This time period is also referred to as the critical period. The importance of a critical period is such that it must involve certain stimuli from which an organisms learns and acquires traits. If some of these stimuli are not present in the critical period, the organism has difficulty acquiring the trait or skill, and may even find it to be impossible to learn the skill.
The answer is FDIC (Federal Deposit Insurance Company)
The current federal program from the New deal that is directly related to the banking industry is the FDIC. This program examines and supervises financial institutions on some factors such as safety and soundness. It promotes and preserves public confidence in the State's financial system.