1. Meteorologist predict the weather by using tools. They use these tools to measure atmospheric conditions that occurred in the past and present, and they apply this information to create educated guesses about the future weather. The best we can do is observe past and present atmospheric patterns and data, and apply this information to what we think will happen in the future. Meteorologists use the scientific method on a daily – and even hourly – basis!
2. They use thermometers, barometers, sling psychrometers and rain gauges. They also use anemometers, hygrometers, weather maps, weather balloons and weather satellites.
Explanation:
The mass of a pot is 300g and contains 90% aluminum. Find the number of moles of aluminum in the pot. P.A. (Al = 27)
The mass of aluminum present in the pot is:

Hence, in the given pot 270g Al is present.

The gram atomic mass of Al -27 g/mol
Given the mass of Al is 270 g
Substitute these values in the above formula:

Answer is 10.0 mol of Al is present.