1)m(CaCO3)=0,75*100=75
2)30<span>Zn 1s22s22p63s23p63d104s2
3)49In </span><span>1s </span>2<span>2s </span>2<span>2p </span>6<span>3s </span>23p6<span>4s </span>23d104p65s24d105p<span>1
</span>
4 39Y <span>1s </span>2<span>2s </span>2<span>2p </span>6<span>3s </span>23p6<span>4s </span>23d104p65s24d<span>1</span>
Щелочи: NaOH,LiOH
Нерастворимые гидроксиды:Mg(OH)2,<span>Fe(OH)3,</span>Cu(OH)2
Приєднання.
CH2=CH2 + Br2 = CH2Br—CH2Br
CH2O2
W(C)=12:46=0,26(26%);
W(H)=2:46=0,0435(4,35%);
W(O)=0,6965(69,65%)