Which of the following types of electromagnetic radiation has the longest wavelength? radio waves ultraviolet waves visible light x-rays

Radio waves

Explanation:

The electromagnetic spectrum consists of  waves having different wavelengths. Wavelength of a wave is defined as the distance between two consecutive crests and troughs. It is inversely proportional to the frequency of the wave.

Out of the given options, the wave having longest wavelength is radio waves. Its wavelength is in between 1 mm to 10,000 km.  

So, the correct option is (a) " radio waves ".      

r just means there's a number of carbon in teh chain. for example rcooh means that after x number of carbon, the chain ends with cooh.

explanation:

"the periodic table is arranged in order of atomic number."