81. Solving a chemistry problem

10. The chemical element is considered - iron.
a) make an electronic formula of the element;
b) determine (underline in the electronic formula) the valence sublevels and graphically represent their electronic structure;
c) determine the number of valence electrons:
d) determine the number of electrons having the value of the orbital quantum number l=0.
e) determine the number of electrons with a combination of quantum numbers n=2 and l=0.