Macroscopic Chemistry
A System for Knowledge Synthesis
A reader for Merrill Sanders' framework. Chemistry described, not explained: no atoms, no molecules, no theory. Begin at the beginning, or pick any concept and follow the typed exits into the rest of the network.
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Take the guided course. Fifty short modules, each one a single concept: it asks what you already think, gives you three readings with a check after each, and ends with a teacher who makes you do the talking. The first seven cover the ground floor and take about two hours.
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The Five Foundational Assumptions. Each builds on the one before.
- Assumption 1
Reality is Real
The world is real and perceivable, independent of human awareness. There is something there to know, and what is there does not depend on us for its existence.
- Assumption 2
World is Composed of Materials
The world is composed of distinct, identifiable materials. Stuff is not one continuous thing; it is made of individual, separate, discrete things that are observable, identifiable, and distinguishable from one another.
- Assumption 3
Phenomena are Interactions
All phenomena result from interactions between materials. Whatever happens in the world happens because things meet, influence one another, and produce change.
- Assumption 4
No Material Disappears
No material disappears without new material appearing. When stuff in the world changes form, it does not vanish; it becomes something else, somewhere else, in some other arrangement.
- Assumption 5
Total Material is Constant
Total material is conserved. The amount of stuff in a closed accounting does not change; it only moves and rearranges. No new matter is created, and no old matter is destroyed.
Curated journeys
Named paths through the network. Each one carries you through a sensible order. Your breadcrumb tracks the rest.
Concepts, relations, systems
The philosophical scaffolding. What a concept is, how concepts relate, and how they assemble into systems where the whole is greater than the sum of the parts.
4 concepts
Through the Five Assumptions
The bedrock layer of the framework, in canonical order. Each assumption builds on the one before.
5 concepts
Materials and how we sort them
From material as a class of things, through phase as the classification primitive, down to the substance / mixture / solution / compound / element hierarchy.
8 concepts
Properties and what we say about them
From the raw idea of a feature to the discipline of measured properties. The chain that makes chemistry quantitative.
8 concepts
Or browse the network
The other concepts. Pick any one as a starting point.
Accidental Feature
An accidental feature is a feature that does not determine a material's identity. Accidental features contribute to a material's overall characteristics without being what makes the material the kind of material it is.
Argumentation
Argumentation is the disciplined movement from assumption to knowledge. It is the skill of identifying what you are taking for granted, gathering evidence, asking hard questions of your own thinking, seeking other perspectives, and revising what you thought you knew.
Assumption
An assumption is a thing that is taken to be true but is not proven to be true. The fundamental ones underwrite everything else.
Assumptive Base
The assumptive base of chemistry is the layer of statements taken to be true before any observing begins. It is the bedrock under which no further inquiry can dig.
Change
A change is a transformation of materials. When materials interact, they change: they become different, they relocate, they take different forms. Change is what makes phenomena visible.
Chemical Potential
Chemical potential is a feature of materials that drives transformation. Where there is a difference in chemical potential between two parts of a system, change tends to occur, until the difference goes away.
Combustion
Combustion is an observable kind of reaction, familiar as burning and rusting, in which a material combines with something from the air (oxygen) and gains mass in the process. Historically it was the case that forced the modern accounting of chemistry into existence.
Composition
Composition is what a material is made of. It is a property of the material; the value of the composition property names the parts that, together, form the whole.
Compound
A compound is a substance that can be separated into elements by electrolysis or thermal decomposition. It has all the features of the substance class plus this one further feature: it comes apart, by these specific methods, into simpler substances.
Concept
A concept is a word or symbol that replaces or represents something in reality. It is the building block of knowledge.
Conservation of Mass
The total mass of materials before a change equals the total mass of materials after, provided nothing has escaped the accounting. This is the quantitative face of the conservation principle, and it is what lets a chemist treat a reaction as an arithmetic problem.
Current Knowledge
Current knowledge is what a learner already knows about chemistry at any given moment. It is not a single number. It is a vector across four dimensions: breadth, accuracy, connectivity, and organization.
Density
Density is the amount of material per unit of space it occupies. It is a property whose value comes from a relation between two other properties: mass and volume.
Descriptive vs. Explanatory
There are at least two types of chemical knowledge, descriptive and explanatory. The first describes things and how they behave; the second attempts to explain why the descriptive does what it does. This site teaches only the first.
Element
An element is a substance that cannot be decomposed by electrolysis or thermal decomposition. It has all the features of the substance class plus this one further feature: under the methods that pull compounds apart, an element holds together.
Energy
Energy is a feature of matter. It does not exist independent of the stuff it belongs to. Together with entropy and chemical potential, it is one of the measurable quantities by which we describe how materials behave and change.
Entropy
Entropy is a feature of matter. Like energy, it does not exist independent of the stuff it belongs to. It is a measurable quantity that, paired with energy and chemical potential, helps describe how materials change and where they come to rest.
Equilibrium
Equilibrium is the settled state a system reaches when the differences in chemical potential within it have closed. At the macroscopic level we recognize it by what we no longer see: nothing appears to be changing further.
Essential Feature
An essential feature is a feature that determines a material's identity. The essential features of a material are what make it the material it is and not some other material.
Extensive Property
An extensive property is a property whose value depends on the size or amount of the material being described. Double the material, and the value of an extensive property doubles with it.
Feature
A feature is an attribute or characteristic of something. Every feature has a value; that is the most important feature of a feature.
First Principles
The First Principles of chemistry are the foundational starting layer of the discipline: the five foundational assumptions together with the rules of argumentation that derive everything else from them. They are where chemistry begins, not what it concludes.
Intensive Property
An intensive property is a property whose value does not depend on the size or amount of the material being described. Cut the sample in half, and the value of an intensive property is unchanged.
Learning
Learning is the change in a learner's current knowledge. It happens when new information connects to what the learner already knows, and it is measured as any one of the four dimensions of current knowledge going up.
Mass
Mass is the amount of matter in a sample, expressed as a number with units. A value for mass must always include a number and measurement units; without both, the value is meaningless.
Material
A material is a member of a class of physical things that share features in common. Materials exist, can be perceived, are composed of matter, and serve as the building blocks of higher units of matter organization.
Measurement
A measurement is a process by which we assign a quantity to a feature. The output of a measurement is a number paired with a unit, and the pair takes its place as the value of a property.
Mixture
A mixture is a material composed of more than one component, in which some property values are not uniform throughout. Its phase_of_matter value is greater than one, and its components are substances that can be separated by methods based on differences in physical features.
Name and Value
Every property has two elements: a name and a value. The pair is ordered: the name comes first, the value second. A property without its value is meaningless.
Necessary Assumption
A necessary assumption is an unstated premise that must be true for an argument's conclusion to follow. If the assumption is false, the argument collapses. The Negation Test is how you find one.
Observation
An observation is the act of perceiving something about the world. The output of an observation is a description, and the name of that description is a property.
Observational Base
The observational base of chemistry is the layer that comes after the assumptions. It uses the concept of a phase to classify matter into mixtures, solutions, compounds, and elements.
Phase
A phase is a uniform region of a material with a single component. Every material has within it some number of regions that appear homogeneous; the count of those regions is the value of the material's phase_of_matter property.
Pressure
Pressure is a feature of a material whose value is what a gauge reads when the material pushes against a known surface. Like temperature, its value belongs to the condition of the material, not to its amount.
Property
Every property has two elements: a name and a value. A property without its value is meaningless.
Reaction
A reaction is an observable transformation in which materials change. At the macroscopic level we recognize a reaction by what can be seen, heard, measured, or felt: a color change, a gas given off, heat released or absorbed, mass that has shifted from one place to another.
Relation
A relation is two concepts and the connection between them. Two related concepts, taken as a whole, are called a relation.
Solution
A solution is a material composed of more than one component, where the value of the phase_of_matter property depends on composition. Its components can still be separated by methods based on differences in physical features.
Substance
A substance is a material whose property values are uniform throughout. It has a phase_of_matter value of one, meaning it is a single component material; substances are the building blocks of mixtures.
Sufficient Assumption
A sufficient assumption is an unstated premise that, if true, guarantees that the conclusion is correct. It closes the gap between the evidence and the conclusion completely. The Affirmation Test is how you find one.
System
A system is a collection of interacting parts. The parts alone are not enough; the interactions between the parts are equally part of what the system is.
Systems Thinking
Systems thinking is the view that how parts work together is as important as the parts themselves, and that a whole can behave in ways no part of it does. It is the deliberate alternative to reductionism.
Temperature
Temperature is a feature of a material whose value is what a thermometer reads when placed in contact with that material. It does not depend on the amount of material, only on its condition.
Universal Process
The universal process is a single generic shape that underlies every transformation we describe. If you understand the generic process, you understand chemical reactions, state transitions, material relocation, diffusion, and even siphons.
Volume
Volume is the amount of space a material occupies. It is a property whose value depends on how much material is present, which makes it extensive.