periodic table Flashcards
1
Q
periods 1-4
A
In the periodic table, periods are rows of elements:
Period 1: 2 elements– 1 electron shell.
Period 2: 8 elements – 2 electron shells.
Period 3: 8 elements – 3 electron shells.
Period 4: 18 elements– 4 electron shells.
As you move across a period, the number of protons and electrons increases.
2
Q
s, p and d block
A
In the periodic table, the s block, p block, and d block refer to sections based on the type of orbitals where the outermost electrons are found.
Summary:
s block: Groups 1-2 and helium.
p block: Groups 13-18.
d block: Transition metals (Groups 3-12).
