It’s easy, if the PH of any acidic solution = -Log[H+], where [H+] is hydrogen ion concentration, multiply each term by (-1) then raise each term as a power to (10), so it will become like this:-
[H+] = 10^(-PH)
        
             
        
        
        
Answer:
Aluminium. 
Explanation:
The above electronic configuration can be written in a simplified form as shown below:
1s² 2s²2p⁶ 3s²3p¹
Next, we shall determine the number of electrons in the atom of the element as follow:
Number electron = 2 + 2 + 6 + 2 + 1
Number of electron = 13
Next, we shall determine the number of protons. 
Since the element is in its neutral state, 
The number of electrons and protons are equal i.e 
Proton = Electron 
Number of electron = 13
Proton = Electron = 13
Proton = 13
Next, we shall determine the atomic number of the element. 
The atomic number of an element is simply the number of protons in the atom of the element i.e
Atomic number = proton number 
Proton = 13
Atomic number = 13
Comparing the atomic number of the element with those in the periodic table, the element with the above electronic configuration is aluminium since no two elements have the same atomic number. 
 
        
             
        
        
        
Idk if this is the information you need but the energy level gets higher the farther you move down the Periodic Table. Every element in a vertical line has the same energy level.