3 Write a word, number or short phrase to answer each question 1 What time does Lizzie's alarm clock ring?
2 What time does Lizzie get to school in the morning!
3 How long does each lesson last?
4 What time does the morning break finish?
5 When is lunch?
6 What time does the photography club start?
7 How many times a week does Lizzie play football?
8 What time does Lizzie go home?
9 On which day does Lizzie have a dance class in the evening?
10 What time does Lizzie go to bed?​

1)

Mr(CaSO3) = Mr = Ar(Ca) + Ar(S) + 3Ar(O) = 40 + 32 + 3 * 16 = 120

w(Ca) = Ar(Ca) / Mr = 40 / 120 = 0.33 = 33%

w(S) = Ar(S) / Mr = 32 / 120 = 0.27 = 27%

w(O) = 3Ar(O) / Mr = 48 / 120 = 0.4 = 40%

2)

Mr(CuO) = Mr = Ar(Cu) + Ar(O) = 64 + 16 = 80

w(Cu) = Ar(Cu) / Mr = 64 / 80 = 0.8 = 80%

w(O) = Ar(O) / Mr = 16 / 80 = 0.2 = 20%

3)

Mr(H2SO4) = Mr = 2Ar(H) + Ar(S) + 4Ar(O) = 2 * 1 + 32 + 4 * 16 = 98

w(H) = 2Ar(H) / Mr = 2 / 98 = 0.02 = 2%

w(S) = Ar(S) / Mr = 32 / 98 = 0.33 = 33%

w(O) = 4Ar(O) / Mr = 64 / 98 = 0.65 = 65%

 А                           железо         магний             медь         цинк

хлорид железа      -                     +                        -                +

хлорид магния       -                    -                        -                  -

хлорид меди          +                   +                       -                  +

хлорид цинка          -                   +                     -                     -

число воз.реак.     1                    3                    0                   2

Б         МАГНИЙ   ЦИНК  ЖЕЛЕЗО     МЕДЬ

С         СuCI2+Fe=Cu+FeCI

           FeCI2+Mg=Fe+MgCI2