Why does so2 and water make h2so3 and not h2so4?

SO2+H2O = H2SO3

To get H2SO4,
SO2 must be oxidized to form SO3, Sulfur tri-oxide
 2SO2+ O2= 2SO3 SO3 can the dissolve in water to form acid rain:

SO3 + H2O = H2SO4

The problem here is that according to aufbau principle before 3d orbital 4s subshell comes.after filling 3p orbital with electrons you have 4 electrons left, you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with the same spin.

The activity series is shown in the attached picture. if the element is below the other, then you can displace the other. following the activity series as a guide, the reactions are as follows: nickel and aluminum chloride3 ni + 2 alcl₃  → 3 nicl₂ + 2 albarium and copper bromideba + cubr  →  no reaction because cu is less oxidizable than bapotassium nitrate and aluminum3 kno₃ + al  → al(no₃)₃ + 3 ksodium phosphate and zincnaso₄ + zn  → znso₄ + na