How many atoms are needed to react with 50 grams of O2 gas

What is the volume occupied by 10.0 dm3 of gas at standard pressure after it has been compressedat constant temputure to 500.0 kpa?

When the speed of the bottle is 2 m/s, the average maximum height of the beanbag is m.

Oil rich countries in the middle east cover about 4% of earths total land area but prossess about 48% of the worlds known oil reserves what is the main reason for high concentration of reserves in this part of the world