Explain what might happen to the number of owls if the amound of grass increased.

The amount of mice and any small creature that eats grass will die off slowly, in turn causes the owls to have less food and die. and it'll just keep going up in the food chain.

The amount of mice and any small creature that eats grass will die off slowly, in turn causes the owls to have less food and die. and it'll just keep going up in the food chain.

The total pressure is the sum of all the partial pressures of the different components in the system. In this case, if the total pressure is 520 torr, and the partial pressure of nitrogen is 266 torr, and the only components are nitrogen and sulfur dioxide, this means that the rest of the pressure is all due to sulfur dioxide.
So the partial pressure of sulfur dioxide = 520 - 266 = 254 torr SO2.