I think it will be zinc. The electron configuration of zinc is:
1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d10
Add up the electrons. 2+2+6+2+6+2+10 = 30 electrons in all, which is the element zinc.
As you can see frorm the above electron configuration, all the electrons for the third energy level are filled: 3s2 is filled; 3p6 is fully filled; 3d10 is fully filled.
I really hope this helps and doesn't confuse you... :)
Neon! =)
The second principle energy level is the energy level that comes after the first principle energy level. The second energy level is farther from the atomic nucleus and contains the 2s and 2p sublevels.
Lithium
Strontium (Sr)
Carbon. Carbon is in the second period, so it has electrons in its second energy level, and it is in the fourth group in the second energy level, so it has 4 electrons.
The element is phosphorus and it contains 5 valence electrons.
5 atoms are located in the second energy level if the first energy level has 7.
The second energy level contains eight valance electrons when it's full.
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Rubidium
The second principle energy level is the energy level that comes after the first principle energy level. The second energy level is farther from the atomic nucleus and contains the 2s and 2p sublevels.
Lithium
The total number of electrons in Phosphorus (P) is 15 (its atomic number). The first energy level contains 2, the second energy level contains 8, and the third energy level contains 5.
Strontium (Sr)
Carbon. Carbon is in the second period, so it has electrons in its second energy level, and it is in the fourth group in the second energy level, so it has 4 electrons.
The element is phosphorus and it contains 5 valence electrons.
The 4th energy level is the lowest that contains and f sub-level
The bottom of the pyramid contains the most energy.