Atomic Radius and Periodic Trends

The second page explores atomic radius trends and their relationship to chemical properties. The atomic radius generally increases moving down a group and decreases across a period.

Definition: Atomic radius is the measure of the size of an atom, influenced by nuclear charge and electron shielding.

Highlight: Electronegativity increases across periods and decreases down groups, measured on the Pauling scale from 0-4.

Example: Fluorine has the highest electronegativity value of 4 on the Pauling scale.

Atomic Structure and Periodic Table Fundamentals

The first page introduces fundamental concepts of atomic structure and electron configuration. The atomic mass unit (1u) equals 1.66×10⁻²⁴ g, establishing the basic unit for atomic mass measurements.

Definition: The atomic number (Z) represents the number of protons, which equals the number of electrons in a neutral atom.

Vocabulary: Electron configuration describes the arrangement of electrons in atomic shells, with each shell having a maximum electron capacity of 2n².

Example: The main electron shells K, L, M, and N can hold 2, 8, 18, and 32 electrons respectively.

Highlight: The filling order of subshells follows a specific pattern, essential for understanding electron configuration and chemical behavior.