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3x+2y+7z=0 3x-2y+7z=0 3x-2y-7z=0 x-2y+7z=0
Y1RQY2RQY3Y4Y5Y6Y7 Y1aY2aY3Y4Y5Y6Y7 Y1aY2Y3Y4Y5Y6aY7 Y1RQY2Y3Y4Y5Y6RQY7
x=4,y=3;x=7,y=8 x=3,y=4;x=7,y=8 x=7,y=8;x=4,y=3 x=8,y=7;x=7,y=8
Y1-RQ-Y2,RQ-Y3-Y4,Y5-Y6-Y7 Y1-a-Y2,a-Y3-Y4,Y5-Y6-Y7 Y1-a-Y2,Y3-Y4-Y5,a-Y6-Y7 Y1-RQ-Y2,Y3-Y4-Y5,QR-Y6-Y7
x=4,y=3;x=7,y=8 x=3,y=4;X=7,y=8 x=7,y=8;x=4,y=3 x=8,y=7;x=7,y=8
x-20y+7z=12 x+20y+7z=12 x+20y-7z=12 x-20y-7z=12
Y1RQY2RQY3Y4Y5Y6Y7 Y1aY2aY3Y4Y5Y6Y7 Y1aY2Y3Y4Y5Y6aY7 Y1RQY2Y3Y4Y5Y6RQY7
(x-)2+y2= (x-)2+y2=3 (x-3)2+y2= (x-3)2+y2=3
x-20y+7z=12 x+20y+7z=12 x+20y-7z=12 x-20y-7z=12
He 和H.互为同位素 He 原子核内中子数为2 He 原子核外电子数为2 He 代表有2个质子和3个中子的氦原子
Y1RQY2RQY3Y4Y5Y6Y7 Y1aY2aY3Y4Y5Y6Y7 Y1aY2Y3Y4Y5Y6aY7 Y1RQY2Y3Y4Y5Y6RQY7
3x+2y+7z=0 3x-2y+7z=0 3x-2y-7z=0 x-2y+7z=0
Y1-RQ-Y2,RQ-Y3-Y4,Y5-Y6-Y7 Y1-a-Y2,a-Y3-Y4,Y5-Y6-Y7 Y1-a-Y2,Y3-Y4-Y5,a-Y6-Y7 Y1-RQ-Y2,Y3-Y4-Y5,Y6-RQ-Y7