# Breaking Bonds

Today I was looking at a torn seam on my jeans.

My jeans are made of cotton, and cotton is made of molecules bonded together.

How many molecular bonds are there in a given area of cotton?

How many bonds are broken each time we sit down, walk around, etc.?

No molecular chemists in the house tonight?

For a WAG, let me suppose that the width of a cellulose molecule is about 1 nanometer (10 angstroms), and just for kicks, let’s suppose the fibers are packed as tightly as possible, so that’s about one fiber in 10^(-18) square meters. If I break this bundle of fibers, I will need to break a covalent bond on each fiber. Actually, the breaks may all occur at the spaces between separate molecules and instead of covalent bonds, I will break a bunch of hydrogen bonds between each fiber and its neighbors, but let’s ignore that. Of course, a cotton fiber won’t be solidly packed cellulose and the threads of the fabric won’t be solidly packed cotton fibers, but we’re talking a seriously huge number of bonds, something like 10^18 per square meter, or 10^14 per square centimeter.