Example of third class Lever first class Lever and second class Lever

Oxygen undergoes an isentropic expansion from 120 degree c and 280 kpa absolute to 140 kpa absolute. determine the final temperature of the oxygen and the amount of work per kg of o_2 produced in the process if it is adiabatic.

Rohit is trying to tune an instrument

An atom that has gained or lost electrons is called an _