what part of a molecule or atom becomes a light particle during combustion?

Question

light particles have mass and can be affected by gravity,they also can travel hundreds of thousands of light years through space unchanged carrying images of its origine.
how are light particles created and what part of an atom do they come from.
what creates its propulsion and determines its direction.

Answer 1

Combustion is an exothermic chemical reaction involving an oxidizing agent (usually oxygen) and a reduced molecule (a hydrocarbon, for example). The chemical energy released goes into the kinetic energy (heat) of the products (CO2, H2O, etc). When molecules or atoms collide, electrons can be excited, which subsequently fall back to the ground state with the emission of a photon. The photon is a quantum of electromagnetic energy known as light. The direction of photon emission (or at least the probability distribution) is determined by the direction of the dipole transition moment. Because molecules in combustion gasses are randomly oriented, the emission is isotropic.

Answer 2

Light has some particle-like properties, but photons do not have rest mass. They have relativistic mass-equivalence due to their speed.

When a carbon atom oxides to form a carbon dioxide molecule, the total number of protons, electrons, and neutrons is unchanged. But the molecule, with some electrons orbiting multiple nucleii instead of just one, has a lower energy. The before-after energy difference determines the energy of the emitted photons. Even with a single atom, if an electron changes energy state, a photon of the appropriate energy is emitted (or absorbed).

I'm not sure enough is known about exactly how this happens to be able to say what determines its direction.