Pls help me out on number 4 and 6 vid; Chemical Reactions that Changed History

Apeak with a retention time of 407 s has a width at half-height (w1/2) of 7.6 s. a neighboring peak is eluted 17 s later with a w1/2 of 9.4 s. a compound that is known not to be retained was eluted in 2.5 s. the peaks are not baseline resolved. how many theoretical plates would be needed to achieve a resolution of 1.5?

What type of electromagnetic radiation has a shorter wavelength than blue light

What three things determine the shape and size of a puddle when water is poured out onto a surface