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Structural and stereochemical notation, reaction mechanism arrows, quantum notation and particle physics. IUPAC governs the chemistry and is cited for it; CODATA and ISO 80000 cover constants and symbols. Several members exist mainly to state a correction that the notation invites and does not contain: a curly arrow never shows an atom moving, a Feynman diagram is not a trajectory, spin arrows do not depict rotation, and a formal charge is a bookkeeping figure rather than a measured one.
A solid triangle showing a bond coming towards the reader.
A ladder of short lines showing a bond going away.
A curved arrow showing where a pair of electrons moves.
A double-shafted open arrow read backwards from the product.
A single dot marking an unpaired electron.
A circled plus or minus on an atom in a structure.
Two dots showing electrons not used in bonding.
A circle inside a hexagon, standing for delocalised electrons.
Italic letters naming the handedness of a stereocentre.
Letters naming which side of a double bond groups sit on.
Reagents above an arrow and conditions below it.
Subscript letters saying whether a substance is solid, liquid, gas or dissolved.
A struck-through h, Planck's constant divided by two pi.
A Greek alpha for a pure number near one over one hundred and thirty-seven.
An epsilon with a zero subscript, in every electrostatic formula.
An overbar marking a particle's antimatter counterpart.
Straight, wavy and coiled lines for different particles.
Angle brackets and a bar denoting quantum states.
A Greek psi standing for a quantum state's amplitude.
A scripted or hatted H standing for a system's total energy.
An arrow with a Greek letter naming the decay mode.
A unit of area for nuclear reaction probability.
Up and down arrows in boxes filling electron orbitals.
Greek letters naming how orbitals overlap in a bond.
Roman numerals in brackets naming an element's oxidation state.
Square brackets around a species, meaning its concentration.
A four-part diamond rating health, fire, reactivity and special hazards.
Standard outlines for flasks, condensers and joints.
How a number is written to state how well it is known.