Answer:
525 Bq
Explanation:
The decay rate is directly proportional to the amount of radioisotope, so we can use the half-life equation:
A = A₀ (½)^(t / T)
A is the final amount
A₀ is the initial amount,
t is the time,
T is the half life
A = (8400 Bq) (½)^(18.0 min / 4.50 min)
A = (8400 Bq) (½)^4
A = (8400 Bq) (1/16)
A = 525 Bq
The correct answer from the list of choices is option C. An example of an observation is when bubbles formed when two chemicals are mixed together. It is an observation because it is what is seen directly by the naked eye after mixing the chemicals.
Please find attached photograph for your answer.
Answer:
C. were formed from plants which did not have time to decay
Explanation:
Coal beds are formed from plants which did not have time to decay. They usually form in an anoxic environment where oxygen is lacking and there is abundant plant matter.
The best place where coal beds can form is in a swamp.
Rapid burial of the plant matter without reacting with oxygen maintains the carbon content and the chemical energy they hound.
Answer:A) he needs to find the net force acting on an object in a direction.
Explanation: