118 Elements and Their Symbols and Atomic Numbers ... to help you remember the first 20 elements of the periodic table: H - Hydrogen He - Helium Li - Lithium Be - Beryllium ...

Earth’s core could contain helium from the early solar system. The noble gas tucks into gaps in iron crystals under high pressure and temperature.

So how has the periodic table been put together ... Any letters that follow will be lower case letters, for example, helium is He. Some element symbols are simple. For example, oxygen is O.Others ...