In the electron configuration [Ar] 4s2 3d10 4p4 which are valence electrons? Chemistry In the electron configuration [Ar] 4s2 3d10 4p4 which are valence electrons? Answer: Both 4s2 and 4p4 If the middle is full than the outside electrons are valence Learn More : Share this Share on FacebookTweet on TwitterPlus on Google+