The two most prominent wavelengths in the light emitted by a hydrogen discharge lamp are 656 nm (red) and 486 nm (blue). Light from a hydrogen lamp illuminates a diffraction grating with 490 lines/mm , and the light is observed on a screen 1.5 m behind the grating. What is the distance between the first-order red and blue fringes?

Two friends at different locations want to communicate with each other by sending low energy signals. which of the following methods can they use to communicate? a) produce x-rays using colliding electrons and send them to radios, which capture sound b) send messages using infrared radiation, which travel in the form of waves c) send radio waves through intervening media like radio and television d) produce sound waves using microwaves from heated objects

What does the mass of 0.7891 mol of ferric oxide (fe2o3)

If 22.5 liters of oxygen reacted with excess of hydrogen, how many liters of water vapor could be produced?