118 Elements and Their Symbols and Atomic Numbers: The periodic table ... which increase sequentially from 1 (Hydrogen) to 118 (Oganesson). Each element has unique chemical properties and is ...

We know this because the hydrogen symbol has a subscript three after it, whereas the nitrogen symbol has no number meaning there’s only one. Chemical reactions can be represented using symbol ...

There are three isotopes of hydrogen: hydrogen ... Z, and different chemical symbol - they are not the same element. If the number of protons changes, then it is a different element.