Identify the neutral element represented by this excited-state electron configuration, then write the ground-state electron configuration for that element 1s22s22p23s1

The number of electrons in ground state and excited state remains the same in this case. So, from electronic configuration;

                                                1s², 2s², 2p², 3s¹

The number of electrons in this element are 7, so for neutral element for seven electrons there are seven protons. Seven protons show that element has atomic number 7. Also the valence shell is 2, means element is present in period 2, and when electron de-excites it will have following configuration,

                                                1s², 2s², 2p³

As the number of valence electrons in this element are 5, so it belongs to group 5.

Result:
          Atomic Number  =  7

          Period  =  2

          Group  =  5

So, element with Atomic number 7, present in Period 2 and Group 5 is Nitrogen.

29.1-12=17.1the answer is this one