Periodic Table and Atomic Structure

This page of the AP Chemistry notes by unit focuses on the periodic table's organization and atomic structure. It serves as a crucial AP Chemistry cheat sheet PDF for students studying Unit 1.

The periodic table is organized into rows (periods) and columns (groups), with elements categorized based on their properties. The guide provides detailed information on the characteristics of metals, non-metals, and metalloids.

Definition: Metals are shiny, conductive, malleable, and typically form positive ions (cations). Non-metals are dull, non-conductive, not malleable, and tend to form negative ions (anions).

Highlight: Metalloids share properties of both metals and non-metals and are often semi-conductors. Examples include boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), and tellurium (Te).

The document explains atomic structure, detailing the components of an atom:

Vocabulary:

• Protons: Positively charged particles in the nucleus
• Neutrons: Neutral particles in the nucleus
• Electrons: Negatively charged particles orbiting the nucleus

The guide introduces the concept of isotopes and ions:

Definition: Isotopes are atoms of the same element with different numbers of neutrons, resulting in different masses.

Example: The notation for isotopes is shown as ₂₆⁵⁶Fe, where 56 is the mass number $protons + neutrons$ and 26 is the atomic number (number of protons).

Definition: Ions are atoms that have gained or lost electrons, resulting in a positive or negative charge.

The document also covers the calculation of average atomic mass:

Formula: Average atomic mass = Σ(isotope mass × relative abundance)

Example: For chlorine, with 75.77% ³⁵Cl (34.969 amu) and 24.22% ³⁷Cl (36.966 amu), the calculation yields an average atomic mass of 35.45 amu.

This AP Chemistry Unit 1 notes PDF provides essential information for understanding the periodic table and atomic structure, making it an invaluable resource for AP Chemistry study guide PDF materials.