Science Guidance · Biology + Chemistry
Science,
from the
atom up.
Guides, tools and sourced charts for biology and chemistry — all on one page.
01 · WHAT IS INSIDE
Two fields, one connected map.
Every topic is a page, and pages link across fields. Read how a protein folds in Biology, then follow the link to the bonds that hold it together in Chemistry.
How living things are built, powered and inherited — from single molecules to whole ecosystems.
What matter is made of and how it changes — atoms, bonds, reactions and the maths that predicts them.
A library that keeps growing
New pages are added over time. Each one is one of four kinds, so you always know what you are opening.
- Guide A topic explained step by step.
- Reference Tables, constants and definitions.
- Tool A calculator or converter you can use.
- Data A chart with its source and numbers.
02 · DATA, SHOWN
Numbers you can see at a glance.
What the human body is made of
Six most abundant elements · approximate share of body mass
Source: Emsley, J. The Elements, Oxford University Press, 1991. By mass.
The pH scale
From strongly acidic (0) to strongly basic (14) · typical values
- −8.0 lemon juice
- −5.0 black coffee
- −3.0 pure water, 25 °C
- −1.9 seawater
- +1.0 household ammonia
03 · TOOLS FOR WORK AND STUDY
Do the calculation, not just read about it.
Small, focused tools that sit next to the guide that explains them. Try the molar mass calculator here.
M = Σ (atomic weight × count)
Atomic weights: IUPAC 2021. Results for pure substances; not applicable to mixtures.
Common questions about ScienceTheGuide
- ScienceTheGuide is a free, browser-based guide to biology and chemistry. Every topic has a plain-language guide, a working calculator and a sourced chart — all on one page. Content is written to align with Khan Academy science scope and verified against primary sources such as NCBI and IUPAC.
- Yes. Every guide, tool and chart is free, with no account required. There are no paywalls and no ads. ScienceTheGuide is modelled on open educational resources such as those published by OpenStax.
- Yes. Every calculator runs entirely in your browser. Nothing you type is sent to any server. This follows the same privacy-by-design approach recommended by UK accessibility guidance.
- Every numerical value cites its source. Atomic weights follow IUPAC 2021 standard atomic weights; physical constants use CODATA 2018 / NIST recommended values; biological data cites peer-reviewed sources such as Molecular Biology of the Cell (NCBI Bookshelf).
- ScienceTheGuide is curriculum-focused: each page covers one concept at a time, pairs a guide with a live tool, and is written for students rather than general readers. Wikipedia is encyclopaedic and broad; ScienceTheGuide is structured around learning paths and exam topics.
Pick a topic. Understand it in one sitting.
Every page: a guide, a tool, a chart. Every value names where it came from.