Atoms and molecules consist of electrons and nuclei. When no bonds exist between atoms, electrons are on discrete energy levels called orbitals: those levels where electrons reside at zero degree Kelvin are called ground states, and those above them are called excited states. Hydrogen spectrum (Balmer experiment) reveals the energy levels in hydrogen atoms, and the results from the dye absorption experiment indicate that large molecules also have energy levels, though they may not be discrete anymore.
Q1- Why does the Balmer series have sharp lines, and dyes have a broad absorption peaks?