Simplified molecular-input line-entry system

The simplified molecular-input line-entry system (SMILES) is a way for scientists to write down and share the structure of molecules in a simple way. It's like writing a secret code for a molecule!

Imagine drawing a picture of a molecule with all the atoms and bonds between them. SMILES helps you write down that picture in one line of letters and numbers.

Let's start by talking about atoms. You know that everything around you is made up of tiny things called atoms. These atoms can bond together to make molecules. Different types of atoms bond together in different ways, forming different molecules.

SMILES uses letters to represent different types of atoms. For example, "C" stands for carbon, "N" stands for nitrogen, and "O" stands for oxygen.

Next, we need to think about bonds between atoms. Just like magnets, atoms can stick together, and the strength of that bond depends on how tightly they stick. SMILES uses different symbols to represent different types of bonds.

The simplest bond is a single line, which means that two atoms are simply stuck together. Sometimes, there can be double or triple bonds, which mean the atoms are stuck together more tightly. SMILES uses "=" for a double bond and "#" for a triple bond.

Now, let's put it all together to write a simple SMILES code for a molecule! Let's say we want to write the structure for water, which is made up of two hydrogen atoms and one oxygen atom.

First, we write the symbols for the atoms: "O" for oxygen and "H" for hydrogen.

Next, we draw in the bonds between the atoms. Oxygen has two single bonds, so we write "H-O-H".

And that's it! "H-O-H" is the SMILES code for water. Scientists can use this code to share the structure of molecules with each other, making it easier to study and understand how they work.

So next time you hear someone talking about SMILES, remember that it's just a secret code for molecules!