About 0.1ev is required to break a hydrogen bond in a protein molecule .calculate the minimum frequency and maximum wavelength of a photon that can accomplish this.

Answer 1

1eV = 1.602*10^-19 Joules
so you have 1.602* 10-20 J
E = h f = h c/L where h = 6.626*10^-34 J s and c = 3*10^8 m/s
so
1.602*10^-20 J = 6.626*10^-34 J s * f
f = 1.602*10^-20 / 6.626*10^-34 Hz = 0.242*10^14= 2.42 *10^13 Hz
and
L = c/f = 3*10^8 / 2.42^10^13 meters