The part of the electromagnetic spectrum that has the longest wavelengths is .

RADIO WAVES

Explanation:

As we know that energy of electromagnetic waves and its wavelength is related by the formula

so here as we can see that energy is inversely depends on wavelength so for the longest wavelength the energy is least.

So here we know that least energy electromagnetic waves are Radio waves.

So the longest wavelength must be corresponding to least energy electromagnetic waves

So here correct answer for longest wavelength will be

RADIO WAVES

when insulating materials rub against each other, they may become electrically charged . electrons , which are negatively charged, may be 'rubbed off' one material and on to the other. the material that gains electrons becomes negatively charged. the material that loses electrons is left with a positive charge.