已知He原子1P11S0跃迁的光谱线在磁场中分裂为三条光谱线。若其波数间距为,则此磁场的磁感应强度B= ____________。今测得,则B=________特斯拉。
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
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