Color implies visible light, so to answer your question: red light has the longest wavelength (~620 - 740 nm). However, there also exists light with even longer wavelengths that is not visible to the human eye, from infrared light to radio waves (with wavelengths that are meters long!)
The pairs are:
K, Kr - Same period
Be, Mg - Same group
Ni, Tc - Both are transition metals
B, Ge - Both are metaloids
Al, Pb - Both form inert oxides
(of a river or road) follow a winding course
Botanist is the type of scientist that studies materials found in plants
I mean I would just assume carbon 12 because the decimal is closer to 12 than 14
