First and Second Laws

First and Second Laws — Internal energy, enthalpy, entropy, and the directionality of spontaneous change.

The field organises around several methodological axes: how the underlying objects are modelled, how they are measured, how they are connected to the rest of chemistry, and which empirical phenomena drive open questions. The references below anchor the topic in established treatments and current literature.

Foundations and core methods

A primary reference for this area is Atkins’ Physical Chemistry (Atkins et al., 2018), which lays out the core concepts that govern first and second laws. The treatment frames the subject within the broader context of thermodynamics and motivates the conceptual vocabulary used throughout this page. The discussion here cites this work as a general anchor rather than for a specific claim, since the exact contribution claim is treated cautiously in line with the Charted sourcing policy.

A complementary perspective comes from Physical Chemistry: A Molecular Approach (McQuarrie and Simon, 1997), which provides further background on the methods and results most relevant to first and second laws. Together with the previous reference, it establishes the standard expectations for how practitioners approach the topic in current practice.

Open questions

Open methodological questions in first and second laws include the transferability of the standard methods to harder regimes, the integration of newer measurement and modelling tools, and the connection to neighbouring subfields of thermodynamics. Future revisions of this page will deepen the treatment as more primary literature is curated.