Answer:
they must have same atomic number and different atomic mass
actual yield of ethanol = 305.0g
molar mass of sucrose = 342g
molar mass of ethanol =46g
mass of sucrose = 665g
mole of sucrose = mass / molar mass = 665/342
mole of sucrose =1.9 mole
sucrose : C2H5OH
1 : 4
1.9 : 1.9x4 =7.6 mole of C2H5OH are formed
mass (therotical yield ) of C2H5OH= mole x mass
mass (therotical yield ) of C2H5OH= 7.6 x 46 = 349.6g
percent yields of ethanol = actual /therotical x100
=305/349.6x100 = 87.24 %
When a electron moves from higher shell to lower shell ,it releases energy because if it goes to lower shell without releasing energy then it will unable to do that so.as lower electron shells have low energy electrons
