Home

Home
Common Compounds
Exam Guide
FAQ
Features
Glossary
Construction Kits
Companion Notes
Just Ask Antoine!
Simulations
Slide Index
Toolbox
Tutorial Index

FAQ
Introduction
Measurement
Matter
Atoms & ions
Compounds
Chemical change
The mole
Gases
Energy & change
The quantum theory
Electrons in atoms
The periodic table
Chemical bonds
Solids
Liquids
Solutions
Acids & bases
Redox reactions
Reaction rates
Organic chemistry
Everyday chemistry
Inorganic chemistry
Environmental chemistry
Laboratory
History of chemistry
Miscellaneous


Home :FAQ :Energy and chemical changePrint | Comment
Previous Question Next Question

Why do different types of change involve different amounts of energy?

Can you tell me which type of energy change involves the most energy? Phase, chemical or nuclear changes? The least? And, just exactly why is this so?
starbuck15@hotmail.com

In general, phase changes absorb or release the least energy and nuclear changes the most. The trend is the result of the different magnitudes for the attractions and repulsions involved in phase, chemical, and nuclear changes. More energy is required to overcome stronger forces- and more energy is released when stronger attractive "bonds" form.

Phase changes involve intermolecular forces. For example, vaporization of water involves snapping hydrogen bonds between water molecules.

Chemical changes involve chemical bonding forces. For example, atomization of water involves snapping two oxygen-hydrogen bonds. Since chemical bonds are much stronger than intermolecular forces, chemical changes require (or release) far more energy than phase changes.

Nuclear changes involve even stronger forces that bind the nucleus together, and so will usually require or release even more energy than chemical changes.

Author: Fred Senese senese@antoine.frostburg.edu



General Chemistry Online! Why do different types of change involve different amounts of energy?

Copyright © 1997-2010 by Fred Senese
Comments & questions to fsenese@frostburg.edu
Last Revised 08/17/15.URL: http://antoine.frostburg.edu/chem/senese/101/thermo/faq/phase-chemical-nuclear-energy.shtml