What is the energy required to remove an electron from an atom?

Which of the following are guidelines to follow for obtaining accurate observations

Mechanical energy is when the amount of kinetic and potential energies added together remains the same. conserved created lost

Two pans of a balance are 24.1 cm apart. the fulcrum of the balance has been shifted 1.33 cm away from the center by a dishonest shopkeeper. by what percentage is the true weight of the goods being marked up by the shopkeeper? assume the balance has negligible mass. answer in units of %.