Why are index fossils used to date other fossils in an area of rock

Assume that the variables x and y are inversely related. if k = 18, what is the value of y for each of the following points? be sure and record your data to be used in the following problem.

What is avogadro’s number, and why is it useful

Which ocean zone has the most abundant primary producer and why a) the abyssopelagic zone ,du to the absence of light and cold water temperatureb) the bathypelagic zone, due to the absence of light and cold water temperaturec) the mesopelagic zone ,due to uts high light availability and warm water temperature d) the epipelagic zone,due to its high light availability and warm water temperature