Final answer:
A spill of 4 million barrels, which equates to 640 million liters, would cover approximately 1280 square kilometers if the oil was spread in a slick one molecule thick.
Step-by-step explanation:
If an oil tanker spilled 4 million barrels of oil into the ocean, we would need to calculate the volume of oil and then the area this would cover if spread one molecule thick. With each barrel containing approximately 160 liters, the tanker would spill a total of 640 million liters of oil. Assuming that an oil molecule is a cube measuring 50 micrometers across, the volume of one molecule would be 125 x 10-18 cubic meters (since 1 micrometer = 10-6 meters). This means each liter of oil, which is 10-3 cubic meters, could contain about 8 x 1015 molecules. Therefore, the 640 million liters would contain approximately 5.12 x 1024 oil molecules.
If we place these molecules side by side to form a single layer, we can calculate the area by squaring the length of one side of a molecule (since the area of a square is side2). The area covered by one molecule would be 2.5 x 10-12 square meters. Multiplying this by the total number of molecules gives us the total area covered, which would be roughly 12.8 x 1012 square meters or about 1280 square kilometers.
Given the magnitude of such a spill, the ecological impact would be substantial, potentially devastating marine life and impacting human activities along the affected coastlines.