Excited state carbon 12

What is the value of keq for the reaction expressed in scientific notation

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?

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.