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 ...

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.

The same chemical symbols are used all over the world ... For example, water is a compound of hydrogen and oxygen, chemically joined together. Each of its molecules contains two hydrogen atoms ...