Simplify the following text for a Grade 11 native English-speaking person.
Original: Oxygen difluoride was first reported in 1929 ; it was obtained by the electrolysis of molten potassium fluoride and hydrofluoric acid containing small quantities of water .
Simplified: Oxygen difluoride was first prepared in 1929 . It was made by the electrolysis of molten potassium fluoride and hydrofluoric acid .