Question

__________ waves can penetrate building easily​

Answer 1

Radio wave can penetrate building easily.

this is the answer of this question.

Answer 2

Gamma rays and radio waves can penetrate building easily.

They both are part of electromagnetic spectrum. Wavelength of gamma rays is less than 10 picometer while wavelength of radio ways is 1 millimetre to 100 kilometre.

This very small and large size of both the waves, enables them to travel through walls. Wavelength is the distance of wave between the crest or trough.