Complex sentence: LiH, especially lithium-7 deuteride, is a good moderator for nuclear reactors, because deuterium has a lower neutron absorption cross-section than aneutronic hydrogen, decreasing neutron absorption in a reactor.
Split into simpler sentences: LiH, especially lithium-7 deuteride, is a good moderator for nuclear reactors. Deuterium has a lower neutron absorption cross-section than aneutronic hydrogen, decreasing neutron absorption in a reactor.