# What Is Heat? Can Heat Capacities Be Negative?

^{1}

^{2}

## Abstract

**:**

## 1. Introduction

## 2. Deficiencies of Bulk Thermodynamics

_{2}obviously shows near-negligible attraction.

## 3. The Self-Gravitating System of the Universe and Atomic Nanoclusters: Do Negative Heat Capacities Exist?

## 4. Conclusions

## Funding

## Institutional Review Board Statement

## Informed Consent Statement

## Conflicts of Interest

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**Figure 1.**Schematic view of Lennard–Jones-type intermolecular potential energy $E$ as a function of distance $r$ (

**left**), and compression factor $Z$ for some representative molecules at room temperature (

**right**). The broken line represents the rigid sphere potential for non-interacting ideal gas atoms, corresponding to $Z=1$. Below this line is the effect for the attractive range of the potential, above the line that for repulsion.

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**MDPI and ACS Style**

Roduner, E.
What Is Heat? Can Heat Capacities Be Negative? *Entropy* **2023**, *25*, 530.
https://doi.org/10.3390/e25030530

**AMA Style**

Roduner E.
What Is Heat? Can Heat Capacities Be Negative? *Entropy*. 2023; 25(3):530.
https://doi.org/10.3390/e25030530

**Chicago/Turabian Style**

Roduner, Emil.
2023. "What Is Heat? Can Heat Capacities Be Negative?" *Entropy* 25, no. 3: 530.
https://doi.org/10.3390/e25030530