Which seismic wave refracts and cannot penetrate the core

P waves and S waves travel through the interior of the earth. P waves are the Primary waves and S waves are the Secondary waves.

    P waves can travel in both solid as well as in liquid (outer core) whereas S wave can travel only through solid. When P waves enters the outer core, it gets deviated and again enters the outer core with further deviation.

               In case of S waves, once it reaches the core-mantle boundary, it reflects to the side of it, forming a shadow zone commonly known as the S wave shadow zone (103°-103°). Thus it cannot penetrate through the outer core.

the transfer of heat by electromagnetic radiation is called thermal radiation . it is usually carried out by electromagnetic waves in an energy range just below the visible spectrum, which is the infrared range.

so the answer would be radiation.

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