Answer:
False
Explanation: isotopes generally have the same physical and chemical properties because they have the same numbers of protons and electrons.
This must be a universal indicator, the pH is going down everytime you add more :)
The answer can be explained when you burn something cleanly (with a very hot item) or not. With a candle lots of Carbon dioxide is producted but when using a bunson burner hardly any CO2 is produced.