A flask contains `3.0xx10^(16)` atoms of He. From This `6.6xx10^(15)` atoms of He are removed. The flask now contains atoms of He

A flask contains 2.0xx10^(13) molecules of CO_(2) . To this 1.5xx10^(14) molecules of CO_(2) are added. The number of molecules in the flask now is

1 gram of hydrogen contains 6xx10^(23) atoms. Then 4 grams of He contains

A flask P contains 0.5 mole of oxygen gas. Another flask Q contains 0.4 mole of ozone gas. Which of the two flask contains greater number of oxygen atoms?

A flask A contains 0.5 mole of oxygen gas. Another flask B contains 0.4 mole of ozone gas Which of the two flasks contains greater number of oxygen atoms.