Matter and Measurement

Classifying matter, SI units, uncertainty, and the quantitative language of chemistry.

Intended level

Beginner — paired with Chemistry Foundations.

Prerequisites

• chemistry-foundations

Ordered lessons

1. si units
2. scientific notation
3. significant figures
4. accuracy precision error uncertainty
5. dimensional analysis
6. density
7. physical vs chemical properties
8. elements compounds mixtures

Related formulas and calculators

• $density$ — see Formula: density
• $percent-error$ — see Formula: percent-error
• unit-converter
• density-calculator

Only links to real, published tools are shown. Placeholders are not linked.

Common misconceptions

• Mass and weight are identical.
• Significant figures are arbitrary rounding rules.
• Volume is the same as mass.

Related resources

• Constants — sourced physical constants with version stamps.
• Laboratory Safety — PPE, hazards, RAMP.
• Glossary — definitions for key terms in this topic.
• Sources and Data — how sources are versioned and cited.

Curriculum mappings

This topic maps to external frameworks stored in src/content/curriculum/. Never implies official affiliation.

• AP Chemistry 1.1 / IB Chemistry 2.1 (see /curriculum/ap-chem-1-1 and file src/content/curriculum/ap-chem-1-1.md).
• Framework version and source URL recorded per mapping; review date 2026-08-21.

Review and source metadata

• Author: Chemistry Fundamentals Editorial Team (chem-team)
• Reviewer: Dr. Example Reviewer (chemistry reviewer — transparent placeholder, see /editorial-policy)
• Last reviewed: 2026-08-21
• Review due: 2027-08-21
• Sources: NIST Reference Placeholder (nist-2022, 2022-CODATA). Placeholder reference — replace with actual sourced reference per lesson.

Printable summary

Summary card (PDF) — coming soon — print styles preserve equations and tables.

Correction? See Corrections Policy and Contact.