Heat in the molecular/atomic scale

  • Context: Graduate 
  • Thread starter Thread starter fandi.bataineh
  • Start date Start date
  • Tags Tags
    Heat Scale
Click For Summary
SUMMARY

The discussion centers on the nature of heat at the molecular scale, particularly in the context of combustion reactions and covalent bond formation. It clarifies that heat is a bulk property resulting from the random motions of particles, which can include but are not limited to vibrational motion. The binding energy released during combustion can manifest as either heat or electromagnetic radiation, with the latter typically emitted as photons that interact with surrounding materials, resulting in an increase in temperature. This distinction emphasizes that heat emission can occur through mechanisms beyond just electromagnetic radiation.

PREREQUISITES
  • Understanding of molecular motion and thermal energy
  • Basic knowledge of combustion reactions
  • Familiarity with covalent bond formation and binding energy
  • Concepts of thermodynamics and energy transfer
NEXT STEPS
  • Explore the principles of thermodynamics, focusing on heat transfer mechanisms
  • Investigate the role of photons in energy transfer during chemical reactions
  • Study the differences between heat and electromagnetic radiation in physical chemistry
  • Learn about molecular dynamics simulations to visualize particle motion and energy distribution
USEFUL FOR

Students and professionals in chemistry, physics, and thermodynamics, particularly those interested in the molecular basis of heat and energy transfer in chemical reactions.

fandi.bataineh
Messages
8
Reaction score
0
what is the physical meaning -and nature- of heat in the molecular scale?
how can molecules emit heat in forms other than EM radiation?

i used to think of thermal energy of matter as the vibrational (kinetic) energy of the atoms/molecules that make up the matter. yesterday i was reading about combustion reactions and covalent bond formation in chemistry subforum; and it was mentioned that;in a combustion reaction; when new covalent bonds are formed; the binding energy of the bonds is emitted in the form of heat OR electromagnetic radiation. that was pretty confusing to me since i used to think of heat EMISSION in the molecular scale simply as EM radiation of energy (the binding energy of the new covalent bonds in the case of combustion reactions) that is emitted by molecules (new molecules that are formed by the new covalent bonds in the combustion reaction) and then absorbed and converted to vibrational (thermal) energy by their surroundings (other molecules/atoms). this obviously conradicts with the phrase "the binding energy of the bonds is emitted in the form of heat OR electromagnetic radiation" because this phrase implies that heat emission and EM emission of energy are two different conceptions, or, in other words, there are means of heat emission other than EM radiations, i wonder what are the other means of heat emission in the atomic/molecular scale? i can't think of the new molecules GAINING vibrational (kinetic) energy and delivering this energy to their surroundings by the mean of collisions; simply because these molecules, which where formed by the new covalent bonds, must LOSE energy, not GAIN it, upon the formations of new bonds.
i hope you will correct me if iam getting these fundamental conceptions incorrectly or if iam missing any other fundamental conceptions or ideas.

i also hope to get full explanation of this phenomenon from a thermodynamic point of view, this is why iam posting this thread here not in the chemistry subforum.
 
Last edited:
Science news on Phys.org
what is the physical meaning -and nature- of heat in the molecular scale?
Individual articles do not have "heat" - heat is a bulk property that describes the energy stored as random motions of the particles. These motions need not be vibrational - though vibrational motion is important.

i was reading about combustion reactions and covalent bond formation in chemistry subforum; and it was mentioned that;in a combustion reaction; when new covalent bonds are formed; the binding energy of the bonds is emitted in the form of heat OR electromagnetic radiation.
... the binding energy is released, usually, as photons ... these photons interact with the surrounding material - heating it up.

When the author says the energy is released as heat - they mean that the overall substance gets warmer.
 
  • Like
Likes   Reactions: 1 person

Similar threads

  • · Replies 11 ·
Replies
11
Views
1K
  • · Replies 15 ·
Replies
15
Views
2K
  • · Replies 20 ·
Replies
20
Views
12K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 8 ·
Replies
8
Views
8K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 5 ·
Replies
5
Views
9K