When the pressure on 2.5 liters of oxygen is decreased from 2.0 atm to 1.0 atm, the volume of the gas
becomes liters.

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Try adding 700% because of the x in y

Small amounts of matter are converted intolarge amounts of energy occurs in both fusion and fission reactions. they are nuclear reactions where a change in the identity or characteristics of an atomic nucleus results when it is bombarded with an energetic particle, as in fission, fusion, or radioactive decay.