Apotassium isotope has a half-life of 1.25 billion years. given that scientists estimate earth's age to be 4.6 billion years, what is the most likely percentage of parent to daughter isotopes of this element currently existing on earth?

a. less than 10 percent
b. 25 percent
c. 50 percent
d. more than 75 percent

Option D

Explanation:

The exponential equation to determine the age of any radioactive object is as follows -

where

Final quantity of isotope after degradation

initial quantity of isotope

half life period of isotope

time period of degradation

Substituting the given values in above equation we get -

Remaining isotope

Hence, option D is correct.

ecological efficiency: % of usable energy transferred as

biomass from one trophic level to the next typical is 10% efficient (90% of

energy is lost),is diagramed as the pyramid of energy flow. then osprey eagle

are tertiary consumer and the shrimp are primary consumer, so to balance

mass of shrimp (1/0.1) / 0.1 = 100 kg 

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