Trends in the Periodic Table Flashcards
1
Q
The first period of elements (shells)
A
fills the 1s orbital / shell 1
H - 1s¹, He - 1s²
2
Q
The second period of elements (shells)
A
fill the second shell - 2s and 2p orbitals 2s: Li Be 2p: B→Ne (6 elements) 8 elements in 2nd period
3
Q
The third period of elements
A
3s and 3p orbitals
3s: Na Mg
3p: Al→Ar
8 elements in 3rd period
4
Q
The fourth period of elements
A
4s, 3d, 4p orbitals
4s: K Ca
4p:
