You should tell your daughter that both carbon and silicon have 4
"valence" electrons, which are the electrons in their outermost shells.
It was this fact that led chemists to try to make the same plastics
(which they had been making with hydrocarbon based petroleums) out of
The very first silicon based plastics that were made in the very early
1900's were believed to have a structure like this:
and anything that has the general structu
Where A and B can be anything, C is a carbon atom and O is an oxygen
atom is called a "Ketone". For example, the chemical name for acetone
is dimethyl ketone because both A and B are methyl groups in acetone.
If you've ever heard of methyl ethyl ketone, you now know why it's
acetone's closest living relative.
So, to name this new plastic, chemists took the name "Silicon" and
combined it with the word "Ketone" and came up with "Silicoketone" which
quickly got shortened to "Silicone". That's why it's Silicon Valley,
but it's silicone caulk.
However, further study showed that the actual structure of silicone
based plastics is this:
Where there are two side groups bonded to each silicon atom (which are
hard to show on a text based venue like this). Every silicone plastic
has the basic structure shown above, but it's the type of side groups
bonded to the silicon atoms that determine the properties of the
So, to recognize the fact that there's no hint of a ketone structure
anywhere in silicon based plastics, the official name of silicon based
plastics have been changed to "siloxanes". But, the silicone name still
sticks, and everyone still uses "silicone" to refer to a silicon based
plastic. It's a mistake that's taken root in our language.
'Silicone - Wikipedia, the free encyclopedia'