What determines how fast a gas diffuses at room temperture

Arollercoaster car at the top of a hill has potential energy kinetic energy chemical energy light energy

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.

Which of the following is in the lanthanide family? a) uranium b) promethium c) silver d) gold