What is the frequency of light whose wavelength is 633Nm

How could a student test the effect of removing heat from a gas that is stored in a sealed container? what must occur in order for matter to change states?

Astable electron arrangement for an atom is one that does not easily change. how is this arrangement arrived at? a. valence electrons are transferred or shared to create a full outer shell of electrons. b. valence electrons are discarded into space to create a full outer shell of electrons. c. protons (positive charge) pair with valence electrons (negative charge) to create a strong bond. d. outer shells with valence electrons are transferred or shared.

How can parts of a solution be separated by chromatography?