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 ...

Helium is a gas made up of atoms ... Compounds are not found on the periodic table. For example, water isn’t on the periodic table because it is a compound, not an element.

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 ...

And generations of children have sung the words, "hydrogen and helium, lithium, beryllium..." in an attempt to memorise some of the 118 elements. This year, the periodic table of chemical elements ...

THE abnormally high heat conductivity of helium II below the λ-point, as first observed by Keesom, suggested to me the possibility of an explanation in terms of convection currents. This ...

The answer is that electronic configurations of atoms are not sufficient to settle this question, just as they do not fully settle the question of where hydrogen and helium should be placed in the ...

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 ...