In the Periodic Table there are elements with low electronegativity (columns at the left of the Periodic Table) and elements with high electronegativity (columns at the right, except the noble gases). This fact is due to their different electronic structure in its outer shell: because of the tendency to have a full shell having 8 electrons, the electropositive elements (those with low electronegativity) tend to lose electrons in favour of the most electronegative ones, that tend to gain electrons, thus forming ions and yielding salts, such as the well known common salt, Sodium Chloride, NaCl. In other compounds, instead of forming ions, the electron cloud shifts from the element with smaller electronegativity towards that having a larger electronegativity.
For instance, in LiF (Lithium Fluoride), Lithium appears as a positive ion because of the loss of an electron , whereas Fluorine appears as a negative ion, since it has gained one electron.
The game we propose today uses 8 elements of low electronegativity (lithium, beryllium, sodium, magnesium, potassium, calcium, rubidium and strontium) and 8 elements of high electronegativity (oxygen, fluorine, sulfur, chlorine, selenium, bromine, tellurium and iodine).
We suggest you to print this image and fold it thorugh any line delimiting the squares containing the chemical elements. The next figure shows an example, folding thorugh the first leftwards line, but you can of course use any fold at any line (horizontal or vertical).
Keep on folding, at lines you may deem convenient, towards any side you like. In our example in next image, we have folded at the lower line.
Repeat this procedure as many times as necessary to fold all 16 squares into just one of them, thus forming a small pack. It does not matter the way you have actually folded.
Now cut the sides of the packet you just folded up. Remember you were folding according to your intuition, as you thought you should do.
Pay attention to the result: some squares are facing up showing the chemical symbols and, obviously, some other are facing down. The surprising fact is that the elements with high electronegativity are clearly separated from the elements of low electronegativity.
Do it and surprise yourself!