What is the name of the element with a valence electron configuration of 2s^22p^4

Since the configuration contains the number 2s and 2p, you can assume that it is in period 2 of the periodic table. By noble gas shorthand, you start with helium, which is atomic number 2. 2s²2p^4 has 2+4 = 6 valence

Add 2+6 = 8, which is Oxygen.