* Neon (Ne) is a noble gas. Noble gases are found in Group 18 of the periodic table and are extremely unreactive. They have a full outer shell of electrons, making them very stable and unlikely to form chemical bonds or participate in chemical reactions.
* Water (H2O) can be decomposed into hydrogen (H2) and oxygen (O2) by electrolysis.
* Nitrous oxide (N2O) can be decomposed into nitrogen (N2) and oxygen (O2) by heating.
* Hydrogen fluoride (HF) can be decomposed into hydrogen (H2) and fluorine (F2) by electrolysis.
In summary, only elements in their elemental form, like neon, cannot be decomposed by a chemical change.
