核电荷数61的是钷,电子层排布是2,8,18,23,8,2
亚层有能级交错现象.各亚层能量由低到高排列如下：
1s,2s,2p,3s,3p,4s,3d,4p,5s,4d,5p,6s,4f,5d,6p,7s,5f,6d.