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Wavelength is the distance from peak to peak of a wave, just imagine wiggling some string: |dw:1438615430691:dw|
So you can see lower frequency of shaking gives a longer wave length, and faster, higher frequency gives a shorter wavelength.
You can also imagine how much more energy it takes to wiggle the string up and down more frequently, energy is directly proportional to the frequency! So if you increase one you increase the other.
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So that should be enough info to answer the first part, the second part you just gotta sorta remember that visible light is higher energy than infrared light. In fact, your body is constantly producing infrared light, from just the molecules of your body having heat. Of course if you were able to heat yourself up like a piece of white hot metal then you can see how much energy it takes to turn infrared light into visible light.
So you're right for the first part, but not the second part.