Answer:
To calculate an electron configuration, divide the periodic table into sections to represent the atomic orbitals, the regions where electrons are contained. Groups one and two are the s-block, three through 12 represent the d-block, 13 to 18 are the p-block and the two rows at the bottom are the f-block.Explanation:
I don’t know about this ♀️
The second one, b synthesis reaction
The answer to your question is : no.of moles of Si = 43/atomic mass of Si = 43/28.1 = 1.53
according to reaction 3 moles of Si gives 1 mole of Si3N4
so 1.53 mole of Si will give 1.53/3 = 0.51 mole of Si3N4
molar mass of Si3N4 = 140.28 g/mole
it means that 1 mole of Si3N4 = 140.28 g
so 0.51 mole of Si3N4 = 0.51 X 140.28 = 71.543 g
D.4s this would be the answer because after eight electrons are added to the third orbital two have to be added to the fourth before more can be added to the third one. The third orbital can hold 18 electrons, but it first has to have eight, then two on the fourth orbital, then the rest of the ten can be added