Someone me this is due i will mark you as a brainliest if answered

K= [Ar] 4s^1

Pb= [Xe]  6s^2 5d^10 6p^2

Sc= [Ar] 4s^2 3d^1

Ra= [Rn] 7s^2

O= [He] 2s^2 2p^4

Ag= [Kr] 5s^2 4d^9

Ru= [Kr] 5s^1

Ce=  [Xe] 6s^2 5d^1 4f^1

I= [Kr] 5s^2 4d^10 5p^5

F= [He] 2s^2 2p^5

All the elements are arranged by melting points on the periodic table. in row they go from metals to gasses. in the row from sodium to argon, sodium is more reactive than the one on its right, magnesium.