Given, half life of a certain radioactive element = 800 years.
Amount of substance remaining at time t = 12.5%
Lets consider the initial amount of the radioactive substance = 100%
Using the half life equation:
A = A₀(1/2)^t/t₁/₂
where A₀ is the amount of radioactive substance at time zero and A is the amount of radioactive substance at time t, and t₁/₂ is the half-life of the radioactive substance.
Plugging the given data into the half life equation we have,
12.5 = 100 . (1/2)^t/800
12.5/100 = (1/2)^t/800
0.125 = (0.5)^t/800
(0.5)^3 = (0.5)^t/800
3 = t/800
t = 2400 years
Thus the object is 2400 years old.
the process of changing one form of energy into another
Answer:
Phosphorus cycle
Explanation:
Biogeochemical cycle, any of the natural pathways by which essential elements of living matter are circlated.
There are four types of biogeochemical cycle, they are ; water cycle,carbon cycle,nitrogen cycle and phosphorous cycle
Carbon cycle is the cycle in which photosynthesis and cellular respiration take place.
Water cycle involves transpiration.
Nitrogen cycle Is the cycle that is dependent upon bacteria for nitrogen fixation and denitrification.
Phosphorus cycle is one of the slowest biogeochemical cycle. It does not stay in the atmosphere, because it is normally in a liquid state at room temperature. It does not include the atmosphere.
Answer:
a.) The garden plants provide energy to all the other organisms. While not every organism consumes garden plants directly, every organism's food lineage can be traced to garden plants. For instance, while ground beetles do not directly consume garden plants, they do eat snails, and snails eat garden plants.
b.) The slug population might increase is the aphid population decreased because there would be less competition for food resources. Both populations consume garden plants, and there is only a finite number of garden plants. Therefore, there is a limit that each population can consume. If there were less aphids eating the garden plants, there would be more left for the slugs. Less starving slugs would lead to greater reproduction and thus a higher slug population.
