Co³⁺: \[\boxed{4s: \quad \boxed{\phantom{\uparrow\downarrow}}\qquad 3d: \quad \boxed{\uparrow}\boxed{\uparrow}\boxed{\uparrow}\boxed{\uparrow}\boxed{\uparrow}\boxed{\phantom{\uparrow}}}\]
Cu²⁺: \[\boxed{4s: \quad \boxed{\phantom{\uparrow\downarrow}}\qquad 3d: \quad \boxed{\uparrow\downarrow}\boxed{\uparrow\downarrow}\boxed{\uparrow\downarrow}\boxed{\uparrow\downarrow}\boxed{\uparrow}}\]
Se²⁻: \[\boxed{4s: \quad \boxed{\uparrow\downarrow}\qquad 3d: \quad \boxed{\uparrow\downarrow}\boxed{\uparrow\downarrow}\boxed{\uparrow\downarrow}\boxed{\uparrow\downarrow}\boxed{\uparrow\downarrow}}\]