The secon row in my periodic table is now done – the alkaline-earth metals – i had to restitch a bit because og wrong counting (the name and short name of strontium was placet to high – and that was very visible)

Here they are:

This group contain, among others, Calcium. Calcium is an important part of calcium carbonate (CaCO₃), which is in limestone, bones, seashells, et cetera.

Some types of calcium carbonate can have variable amounts of magnesium or strontium incorporated, vere they then replace calcium. They can do this because they have the same amount of valence electrons (in the same type of orbitals, here the s-orbital) – the valence electrons are illustrated by the light coloured perls in my table. Naturally their sizes has to be teken into consideration and therefore this can not happen i alle types of calcium carbonate

These relations down each group i partly why the periodic table is such a practical tool.

I an already stitching the next couple of elements and it is starting to look like a table, so I will give you a little sneak peak.