1. Metals, Nonmetals, and Metalloids:
Metals: Alkali metals (Group 1), Alkaline earth metals (Group 2), Transition metals (Groups 3-12), Lanthanides (Group 3), Actinides (Group 3)
Nonmetals: Halogens (Group 17), Noble gases (Group 18)
Metalloids: B, Si, Ge, As, Se, Te
2. Periods:
Periods are horizontal rows of the periodic table, with elements increasing in atomic number from left to right.
There are 7 periods in the periodic table.
3. Groups or Families:
Groups are vertical columns of the periodic table, with elements having similar chemical properties due to the same number of electrons in their outermost energy level.
There are 18 groups in the periodic table.
4. Blocks:
s-block: Elements in the first two columns (Groups 1 and 2) of the periodic table.
p-block: Elements in columns 13-18 of the periodic table.
d-block: Transition metals in columns 3-12 of the periodic table.
f-block: Lanthanides and Actinides in columns 3 and 3 of the periodic table.
5. S blocks and P blocks:
s-block: The first two rows of the periodic table, with elements having one or two valence electrons.
p-block: The next five rows of the periodic table, with elements having three or more valence electrons.
6. Periodic Trends:
Atomic radius decreases as you move from left to right across a period.
Atomic radius increases as you move down a group.
Reactivity increases as you move from left to right across a period.
Reactivity decreases as you move down a group.
These are some of the ways the periodic table can be classified. Each classification system helps to organize the elements and understand their properties and relationships.
