How does a neutral atom change when its number of protons, electrons, or neutrons changes?

How many atoms of nitrogen are in the chemical formula ni(w on

The two most prominent wavelengths in the light emitted by a hydrogen discharge lamp are 656(red) and 486 (blue). light from a hydrogen lamp illuminates a diffraction grating with 500 lines per mm, and the light is observed on a screen 1.50 behind the grating. what is the distance between the first-order red and blue fringes?

1. what is the si unit of emf? 2.a complete series circuit consists of a 12.0 v battery, a 4.70 ω resistor, and a switch in the closed position. the internal resistance of the battery is 0.30 ω. what does an ideal voltmeter read when placed across the resistor?