Which electron configuration could represent the electrons in a Sodium atom in an excited state?

One significant difference between an ionic bond, where electrons are taken from one atom and added to another atom, and a covalent or metallic bond, where electrons are shared is

Idon’t know how to solve this question

Joe shines white light into a bowl half full of water at an angle of incident of 27.5°. calculate the angle of refraction in the water given the indices of refraction for air and water are 1.00 and 1.36, respectively.