![color coded periodic table with gases color coded periodic table with gases](https://www.thoughtco.com/thmb/4FcOhHpMh3sVY0M68AdmLEFIpeY=/2200x1701/filters:no_upscale():max_bytes(150000):strip_icc()/PeriodicTableallcolor-58b5c82c3df78cdcd8bbb80f.png)
With a chemical reaction even though chemical bonds have been broken and reformed to create a new chemical, we haven't touched the protons in the nucleus and therefore haven't changed the elements involved. Which as we know is a chemical compound composed of the elements hydrogen and oxygen. Using the hydrogen and oxygen gas example, if we added those gases together and introduced a source of heat like a flame, they would react and combine to form water.
![color coded periodic table with gases color coded periodic table with gases](http://xaktly.com/Images/Chemistry/Chemistry_PeriodicByType.png)
Now there is enough energy to break chemical bonds and conduct a chemical reaction where the atoms of different elements can combine into a compound composed to atoms from both elements. For example, if I combine hydrogen and oxygen gas together at low temperatures then I just have a vessel filled with unreacted gas.Ģ) At higher energies we start creating the situation suitable for reactions to occur. You just get a mixture of different types of atoms. Combining two atoms of different elements together depends on how much energy you put into such a collision.ġ) At low energies (think low temperatures essentially) putting together two samples composed of atoms of different elements doesn't usually create a reaction. So in practice we're not really combining elements rather atoms of different elements. So elements are different types of atoms which are differentiated by their atomic number (the number of protons).