Periodic Table Organization

The periodic table is a tabular arrangement of elements, organized by their atomic number (number of protons in the nucleus), electron configuration, and recurring chemical properties.
The table is divided into rows called periods and columns called groups or families.

There are 7 periods in the periodic table, each representing a new energy level.
Elements in the same period show trends in atomic radius, electronegativity, and ionization energy.

There are 18 groups in the periodic table, each representing a new set of recurring chemical properties.
Elements in the same group show similar chemical behavior due to the same number of electrons in their outermost energy level.

Metals: typically shiny, malleable, and good conductors of electricity (left side and center of the periodic table).
Nonmetals: typically dull, brittle, and poor conductors of electricity (right side of the periodic table).
Metalloids: exhibit some properties of metals and some properties of nonmetals (border between metals and nonmetals).

The periodic table is divided into s, p, d, and f blocks, based on the orbital type of the last electron added.
s-block: elements in groups 1 and 2, characterized by a single electron in the outermost energy level.
p-block: elements in groups 13-18, characterized by a partially filled p subshell.
d-block: elements in groups 3-12, characterized by a partially filled d subshell.
f-block: elements in the lanthanide and actinide series, characterized by a partially filled f subshell.

Atomic radius: decreases from left to right across a period and increases down a group.
Electronegativity: increases from left to right across a period and decreases down a group.
Ionization energy: increases from left to right across a period and decreases down a group.

Alkali metals: group 1, characterized by a single electron in the outermost energy level and highly reactive.
Alkaline earth metals: group 2, characterized by two electrons in the outermost energy level and less reactive than alkali metals.
Halogens: group 17, characterized by seven electrons in the outermost energy level and highly reactive.
Noble gases: group 18, characterized by a full outermost energy level and unreactive.

The periodic table is arranged according to atomic number, electron configuration, and recurring chemical properties.

There are 7 periods, each representing a new energy level.
Elements in the same period show trends in: • Atomic radius • Electronegativity • Ionization energy

There are 18 groups, each representing a new set of recurring chemical properties.
Elements in the same group show similar chemical behavior due to the same number of electrons in their outermost energy level.

Metals: • Typically shiny • Malleable • Good conductors of electricity • Located on the left side and center of the periodic table
Nonmetals: • Typically dull • Brittle • Poor conductors of electricity • Located on the right side of the periodic table
Metalloids: • Exhibit some properties of metals and some properties of nonmetals • Located on the border between metals and nonmetals

The periodic table is divided into s, p, d, and f blocks based on the orbital type of the last electron added.
s-block: • Elements in groups 1 and 2 • Characterized by a single electron in the outermost energy level
p-block: • Elements in groups 13-18 • Characterized by a partially filled p subshell
d-block: • Elements in groups 3-12 • Characterized by a partially filled d subshell
f-block: • Elements in the lanthanide and actinide series • Characterized by a partially filled f subshell

Atomic radius: • Decreases from left to right across a period • Increases down a group
Electronegativity: • Increases from left to right across a period • Decreases down a group
Ionization energy: • Increases from left to right across a period • Decreases down a group

Alkali metals: • Group 1 • Characterized by a single electron in the outermost energy level • Highly reactive
Alkaline earth metals: • Group 2 • Characterized by two electrons in the outermost energy level • Less reactive than alkali metals
Halogens: • Group 17 • Characterized by seven electrons in the outermost energy level • Highly reactive
Noble gases: • Group 18 • Characterized by a full outermost energy level • Unreactive