Hello, this week we're almost at the top of the periodic table because we're taking a look at the lighter than air gas helium. But for this chemist a helium filled bobbing balloon is actually a source ...

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 ...

Just four years before Mendeleev announced his periodic table, Newlands noticed that there were similarities between elements with atomic weights that differed by seven. He called this The Law of ...

If an atom has 2 protons, that’s an atom of the element helium. If it has 7 protons, that’s nitrogen. But the logic of the periodic table also relies upon the number and organisation of electr ...