Factors contributing to faster weathering of limestone in southern Florida:

* Climate: Southern Florida has a tropical climate with high temperatures, abundant rainfall, and high humidity. These conditions promote chemical weathering processes, such as dissolution and hydrolysis, which break down limestone.

* Chemical composition: Limestone is primarily composed of calcium carbonate, which is highly soluble in acidic rainwater. The acidic rain is a result of atmospheric pollution and natural processes like the decomposition of organic matter.

* Biological activity: Southern Florida has a diverse ecosystem with abundant plant life and microorganisms. These organisms produce acids that contribute to weathering.

Factors contributing to slower weathering of granite in northern Canada:

* Climate: Northern Canada has a cold, dry climate with long winters and limited rainfall. These conditions inhibit chemical weathering processes.

* Chemical composition: Granite is composed of quartz, feldspar, and mica, which are relatively resistant to chemical weathering.

* Physical weathering: Granite is more susceptible to physical weathering processes, such as frost wedging and abrasion, but these processes are less effective in breaking down the rock compared to chemical weathering.

Conclusion:

The combination of a tropical climate, chemical composition, and biological activity in southern Florida creates an environment that promotes rapid weathering of limestone. In contrast, the cold, dry climate and resistant composition of granite in northern Canada result in slower weathering rates.