B - <span>1s </span>2<span>2s </span>2<span>2p </span><span>1
P - </span><span>1s </span>2<span>2s </span>2<span>2p </span>6<span>3s </span>23p<span>3
Mn - </span><span>1s </span>2<span>2s </span>2<span>2p </span>6<span>3s </span>23p6<span>4s </span>23d<span>5
Br - </span><span>1s </span>2<span>2s </span>2<span>2p </span>6<span>3s </span>23p6<span>4s </span>23d104p<span>5
Sr - </span><span>1s </span>2<span>2s </span>2<span>2p </span>6<span>3s </span>23p6<span>4s </span>23d104p65s<span>2</span>
M(H2SO4)=19.6г M(H2SO4)=98г/моль n(H2SO4)= m/M=19.6/98=0.2моль
N=Nₐ *n N=6.02*10²³ *0.2=1.204 *10²³молекул