NCERT Class 11
Why does Chromium have the configuration [Ar]3d⁵4s¹ instead of [Ar]3d⁴4s²? Half-filled stability breaks the Aufbau rule. Explore the orbital clouds in 3D.
Every element has a unique 'fingerprint' of light lines. Hydrogen's visible lines — red, blue-green, violet — form the Balmer series. Watch them appear as electrons cascade down.