Complex sentence: For X-rays and gamma rays the gray is numerically the same value when expressed as the sievert (Sv), but for alpha particles one gray is equivalent to twenty sieverts because of the radiation weighting factor that is applied.
Split into simpler sentences: For X-rays and gamma rays the gray is numerically the same value when expressed as the sievert (Sv). But For alpha particles one gray is equivalent to twenty sieverts because of the radiation weighting factor that is applied.