ALKALI METALS IN WATER

Somehow, I never get tired of adding alkali metals to water!

Thanks to KM for recording this on his new cellphone.

HYDROGEN LINE SPECTRA ANIMATION

You can use this Flash animation to help you understand the Bohr model of the atom, and how the transition of electrons from one energy state to another is linked to the absorption or emission of a photon.
Remember Mr Leath's nmemonic: "Little Bo Peep" for Lyman, Balmer and Paschen, the series you need to memorise for the exams!