Answer: The rock is 2000785 years old.
Explanation:
Expression for rate law for first order kinetics is given by:

where,
k = rate constant
t = age of sample
a = initial amount of the reactant = 800
x = amount of daughter isotope = 600
a - x = amount left after decay process = amount of parent isotope = (800-600) = 200
Half life is the amount of time taken by a radioactive material to decay to half of its original value.




The rock is 2000785 years old.
I think the answer is plate movement. Tectonic plate movement is the movement on the lithosphere. This movement is defined into three; we have the convergent, divergent and transform. Plate movements often caused volcanic eruptions as well as earthquakes, depending on the movement on the plates.
Tourism is the LARGEST industry in the world.
Factors which caused an Increase in Air Pollution in China:
A.) Coal Combustion
B.) Slash and Burn
C.) Excessive disposal of Garbage into Open Area
Hope this helps!