What Is Chemistry? Research Areas, Funding, and Career Paths

Chemistry is the branch of science that studies matter — its composition, structure, properties, and the transformations it undergoes when substances react with one another. Chemists work at the level of atoms, molecules, and the bonds that hold them together: what a substance is made of, why it behaves the way it does, and what happens, energetically and structurally, when it changes into something else. Chemistry is often called the “central science” because it sits between physics, which explains the fundamental behavior of matter and energy at the smallest scales, and biology, which studies the living systems built from chemical processes — nearly every other natural science depends on chemical concepts to explain how its own subject matter actually works.

What Chemistry Actually Studies

At its core, chemistry asks a small set of recurring questions: What is this substance made of? How are its atoms arranged and bonded? How much energy does it take to break or form those bonds? How fast does a given transformation happen, and what determines that rate? And how can a desired substance be made, purified, and verified? Those questions recur across every branch of the field, from a first-year general-chemistry course to an active synthetic-methodology research program.

• Composition and structure — identifying what elements and functional groups make up a substance, and how its atoms are connected and arranged in three-dimensional space.
• Bonding and structure-property relationships — explaining why a substance has the physical and chemical properties it has (melting point, solubility, reactivity, color, conductivity) in terms of its bonding and structure.
• Chemical reactions and mechanisms — the step-by-step pathway by which reactants become products, including which bonds break and form and in what order.
• Thermodynamics and kinetics — whether a reaction is energetically favorable at all (thermodynamics), and, separately, how fast it actually proceeds under real conditions (kinetics).
• Synthesis — the deliberate, planned construction of a target molecule or material from simpler starting materials, often the practical endpoint of a research question.
• Analysis and characterization — confirming what was actually made or what a sample actually contains, using instrumental and classical methods, rather than assuming it from the reaction plan alone.

Because these questions apply to essentially any form of matter, chemistry is both a foundational science in its own right and a toolkit that nearly every other physical and life science borrows directly — a materials scientist, a pharmacologist, and an environmental engineer are all, in some part of their work, doing chemistry.

A Brief History of Chemistry

Chemistry’s roots lie in alchemy — a centuries-long, pre-scientific tradition across the Islamic world, medieval Europe, and elsewhere that combined genuine practical technique (distillation, extraction, metallurgy) with mystical and often secretive goals like transmuting base metals into gold. The transition to chemistry as an experimental science is conventionally dated to the late eighteenth century, when Antoine Lavoisier established the law of conservation of mass and overturned the earlier phlogiston theory of combustion — work substantial enough that Lavoisier is widely credited as a founder of modern chemistry. The nineteenth century then supplied the field’s organizing structure: John Dalton’s atomic theory gave chemistry a physical model of matter built from discrete atoms, and Dmitri Mendeleev’s 1869 periodic table organized the known elements by recurring chemical properties, correctly predicting the existence and properties of several elements not yet discovered. The twentieth century added the quantum-mechanical explanation for why bonding and periodicity work the way they do, and produced the instrumental methods (spectroscopy, crystallography, chromatography, and eventually computational chemistry) that let chemists characterize structure and monitor reactions with a precision earlier chemists could not have had. That instrumentation is also what turned chemistry into the highly quantitative, evidence-dense research discipline it is today, rather than the largely descriptive science it had been for most of its history.

How Chemistry Relates to Neighboring Disciplines

Chemistry’s boundaries with adjacent sciences are porous, and a great deal of active research sits explicitly at those boundaries:

• Physics supplies the fundamental theory — quantum mechanics, statistical mechanics, thermodynamics — that explains why atoms bond the way they do; physical chemistry is largely the application of that theory to chemical systems. See CASRAI’s companion guide on what physics studies for the broader picture.
• Biology depends on chemistry to explain how living systems actually work at the molecular level — metabolism, genetics, and cell signaling are all, mechanistically, chemistry happening inside a cell. CASRAI’s guide to what biology studies covers the broader life-science picture this connects to.
• Biochemistry is the most direct overlap of all: it applies chemical methods and reasoning specifically to the molecules and processes of living organisms. See CASRAI’s guide to biochemistry for how the two fields divide the same territory.
• Pharmacology and medicinal chemistry apply chemical synthesis and structure-activity reasoning to the design and action of drugs; see CASRAI’s guide to pharmacology.
• Toxicology uses chemical structure and dose-response reasoning to understand how substances cause harm, a question that is inseparable from the underlying chemistry of the substance itself; see CASRAI’s guide to toxicology.
• Molecular biology and chemistry share substantial common ground in the chemistry of nucleic acids and proteins; see CASRAI’s guide to molecular biology.
• Materials science, geology, and environmental science all apply chemical principles to, respectively, engineered materials, the composition of the earth, and pollutants and natural chemical cycles in the environment.
• Computer science increasingly intersects with chemistry through computational and quantum chemistry, cheminformatics, and machine-learning-driven molecular design; see CASRAI’s guide to computer science for that broader picture.

Major Branches of Chemistry

Chemistry is typically divided into a handful of major subfields, though a great deal of real research now sits deliberately across more than one of them:

• Organic chemistry — the chemistry of carbon-containing compounds, which make up the overwhelming majority of known chemical substances, including nearly all pharmaceuticals, polymers, and biomolecules. Organic chemists focus heavily on synthesis: building complex molecules step by step from simpler starting materials.
• Inorganic chemistry — the chemistry of everything else: metals, minerals, coordination compounds, and organometallic compounds that combine organic and inorganic character. Inorganic chemistry underlies catalysis, battery and materials chemistry, and much of industrial chemistry.
• Physical chemistry — the quantitative, theory-driven study of why chemical systems behave as they do: thermodynamics, kinetics, quantum chemistry, and spectroscopy all sit here. Physical chemistry supplies much of the conceptual and mathematical foundation the other branches build on.
• Analytical chemistry — the development and application of methods to identify and quantify what a sample actually contains, from classical titrations to modern instrumental methods like mass spectrometry and chromatography. Analytical chemistry underpins quality control, forensics, environmental monitoring, and verification work across every other branch.
• Biochemistry — the chemistry of biological molecules and processes, covered in depth in CASRAI’s dedicated biochemistry guide; it is frequently taught and funded as its own discipline rather than strictly as a chemistry subfield.
• Materials chemistry — the design and synthesis of new solid-state and polymeric materials with targeted properties (conductivity, strength, porosity), heavily overlapping with materials science and engineering.
• Medicinal chemistry — the design, synthesis, and structure-activity optimization of candidate drug molecules, sitting at the boundary of organic chemistry and pharmacology.
• Environmental chemistry — the study of chemical processes in air, water, and soil, including pollutant behavior, atmospheric chemistry, and remediation chemistry.
• Computational and theoretical chemistry — using quantum-mechanical calculations and molecular simulation to predict structure, reactivity, and properties, often ahead of or alongside laboratory synthesis.
• Nuclear and radiochemistry — the chemistry of radioactive isotopes and nuclear processes, with applications spanning medical imaging and therapy, nuclear energy, and dating techniques.
• Polymer chemistry — the synthesis and characterization of large, repeating-unit macromolecules, spanning plastics, fibers, and biomedical polymers.
• Green and sustainable chemistry — the design of chemical products and processes that reduce or eliminate hazardous substances, a set of principles that now cuts across essentially every branch above rather than standing apart as a separate discipline. CASRAI’s practical green chemistry lab guide covers solvent, reagent, and setup selection in more operational detail.

Who Funds Chemistry Research

This is the piece a general encyclopedia entry on chemistry typically skips, and it matters if you are trying to understand the field as a research enterprise rather than only as a body of knowledge. In the United States, basic and applied chemistry research is funded through several federal routes, each with a somewhat different emphasis:

• The National Science Foundation (NSF) — within NSF’s Directorate for Mathematical and Physical Sciences, the Division of Chemistry (CHE) is the primary home for fundamental chemistry research across essentially all the major subfields (synthesis, catalysis, physical and analytical chemistry, chemical measurement and imaging), funded independent of any specific disease or industrial application.
• The Department of Energy (DOE) Office of Science — through its Office of Basic Energy Sciences (BES), DOE is one of the largest funders of fundamental chemical sciences research in the United States, with particular emphasis on catalysis, materials chemistry, separations chemistry, and the physical chemistry underlying energy conversion and storage. BES also operates several of the national user facilities (synchrotron light sources, neutron sources) that chemists rely on for structural characterization work that isn’t available at a typical university lab.
• The National Institutes of Health (NIH) — chemistry research with a biomedical framing, particularly medicinal chemistry, chemical biology, and the chemistry of drug design and delivery, is funded through NIH, often via the National Institute of General Medical Sciences (NIGMS), which supports basic, non-disease-targeted chemical biology alongside the other basic biomedical sciences; disease-specific medicinal chemistry projects are more often funded by the relevant disease-focused institute instead.

Beyond the three main federal funders, the major early-career foundation fellowships CASRAI has already documented — including the Searle Scholars Program — regularly fund early-career chemists alongside researchers in adjacent physical and life-science fields, though none of them is chemistry-exclusive. Professionally, the American Chemical Society (ACS) is the field’s largest scientific society and, through its ACS Petroleum Research Fund and various divisional and travel awards, is also a genuine (if smaller-scale) funding source, alongside its better-known roles as a major chemistry publisher and standards-setter for chemical nomenclature and manuscript conventions.

None of this is an exhaustive funding directory — program names, paylines, and eligibility rules change, and a researcher planning an actual application should verify current program scope directly against NSF CHE’s, DOE BES’s, or NIGMS’s own current guidance rather than treating this summary as current-as-of-application-date.

Typical Research Methods, Tools, and Equipment

Chemistry research spans a common set of instrumental and computational methods, though the specific mix in use varies a great deal by subfield:

• Spectroscopy — nuclear magnetic resonance (NMR) spectroscopy, infrared (IR) spectroscopy, and UV-visible (UV-Vis) spectroscopy are the workhorse methods for confirming molecular structure and monitoring reactions, each reporting on a different aspect of a molecule’s structure or electronic behavior.
• Mass spectrometry — used to determine molecular weight and structural fragmentation patterns, often coupled directly to a chromatography step for combined separation and identification.
• Chromatography — gas chromatography (GC) and high-performance liquid chromatography (HPLC) separate the components of a mixture, both for purification and for quantitative analysis; CASRAI’s GC-MS vs LC-MS comparison covers how the two combined techniques differ in practice.
• X-ray crystallography — determines the precise three-dimensional atomic structure of a crystalline sample, the definitive method for confirming a molecule’s exact structure when a suitable crystal can be grown.
• Computational and quantum chemistry software — used to model electronic structure, predict reaction outcomes, and rationalize experimental results, increasingly run alongside, not just after, laboratory synthesis.
• Standard synthesis and handling equipment — fume hoods, Schlenk lines and gloveboxes for air- and moisture-sensitive chemistry, rotary evaporators, and standard glassware remain the everyday infrastructure of a working synthetic chemistry lab, alongside the electronic lab notebooks (ELNs) increasingly used to record and search reaction data; see CASRAI’s guide to electronic lab notebooks for chemistry for how reaction and structure data specifically get captured.

Chemistry labs also depend on a specific procurement and safety infrastructure — controlled reagent storage and dispensing, chemical inventory tracking, and hazard classification — that CASRAI’s chemistry stockroom guide covers in operational detail, and on public chemical data infrastructure like PubChem, the NIH/NLM repository of chemical compound and bioassay data that chemists across many subfields use to look up and cross-reference known compounds.

Career and Training Pathways

A research career in chemistry typically starts with a bachelor’s degree in chemistry or a closely related field, often including an ACS-approved curriculum at institutions that offer one. Graduate training normally means a PhD (typically five to six years in the United States), structured around coursework, a set of qualifying or cumulative exams, and a dissertation built on original research conducted in a faculty advisor’s lab. Many chemistry PhDs, particularly in synthetic, physical, and computational chemistry, go on to one or more years of postdoctoral research before an independent faculty or industry research position, though industrial chemistry (particularly in pharmaceuticals, materials, and specialty chemicals) also hires directly at the PhD or even bachelor’s/master’s level for many roles.

The American Chemical Society (ACS) is the field’s dominant professional society in the United States, publishing a large share of the discipline’s major journals, setting widely used manuscript and nomenclature conventions (see CASRAI’s guide to ACS style and chemistry manuscript conventions), and administering the ACS Standardized Exams used in many undergraduate programs. Internationally, the Royal Society of Chemistry (RSC) plays a broadly similar role in the UK and publishes a substantial share of the field’s journals as well. Chemists publishing early findings ahead of peer review increasingly use ChemRxiv, the discipline-specific preprint server for chemistry.

Frequently Asked Questions

What are the main branches of chemistry?
The five branches most commonly taught as the field’s core divisions are organic, inorganic, physical, analytical, and biochemistry, though materials, medicinal, environmental, computational, nuclear, polymer, and green chemistry are all well-established subfields in their own right, and much current research deliberately sits across more than one branch.

Is chemistry a natural science or a physical science?
Both terms are used, and correctly — chemistry is one of the physical sciences (alongside physics, astronomy, and the earth sciences), and the physical sciences are, in turn, one of the two broad divisions of the natural sciences, the other being the life/biological sciences.

What is the difference between chemistry and biochemistry?
Chemistry studies matter and its transformations generally, across any substance; biochemistry applies chemical methods and reasoning specifically to the molecules and processes inside living organisms. In practice the two fields overlap heavily and often share departments, journals, and funding sources — see CASRAI’s what is biochemistry guide for the fuller comparison.

What can you do with a chemistry degree?
Chemistry graduates work in pharmaceutical and biotech research and development, materials and specialty-chemical industries, environmental and forensic analysis, chemical education, patent law and regulatory affairs, and, for those pursuing a PhD, academic or national-laboratory research; the specific path depends heavily on which branch of chemistry a researcher specializes in and the level of degree completed.

How is chemistry research typically funded in the United States?
Mainly through the National Science Foundation’s Division of Chemistry, the Department of Energy’s Office of Basic Energy Sciences, and, for biomedically framed chemistry, the National Institutes of Health — see the funding section above for how the three divide the field’s territory.

Where Chemistry Fits Among the Sciences

For a broader map of how chemistry relates to the full set of major scientific disciplines — from physics and astrophysics through to biology and epidemiology — see CASRAI’s overview guide to the branches of science, which this page is part of a companion series alongside.