What is the chemical symbol for the atom with an electron configuration 1s^22s^22p^63s^1

Na (Sodium)

Explanation:

The reason it is Sodium (Na) is because, counting on the periodic table there are those levels. Reading left to right, Hydrogen and Helium are 1s2, Dropping to Lithium and Beryllium that's 2s2, Moving straight across to Boron-Neon that is 2p6, 3s1 is then Sodium as it is in that 3rd row and the first one which is what the exponent corresponds to. The two left columns are the S orbital, the 6 right across from it for example Boron to Neon are the P orbitals. Eventually you will get to the D orbitals that's Sc-Zn, but that's not used in this question. Like I mentioned the exponent corresponds to the number of elements that are in that orbital. if you were to count up every exponent you should be able to get the Atomic Number!

Follow up with a comment if you have any more questions.

10 years is the answer