> There is a resonant frequency of liquid water Yes, I'll give you that > in the microwave range No. Water's first resonance is around 1THz, in the far infr

> There is a resonant frequency of liquid water Yes, I'll give you that > in the microwave range No. Water's first resonance is around 1THz, in the far infrared. > which is why tabletop microwaves use that range. No, they use 2.4GHz because that is what the FCC lets them use. The first microwave oven used 1GHz (https://www.google.com/patents/US2480679 https://www.google.com/patents/US2480679), later increased to 3GHz (https://www.google.com/patents/US2495429 https://www.google.com/patents/US2495429). Anything in that range will work.