Comparative strength of sigma bonds

[Jeffrey Hablewitz 2I]

How can you determine the comparative strength of single bonds? For example, how would you determine if a single bond between a carbon and nitrogen is stronger than a single bond between a carbon and oxygen? Does it have something to do with the difference in electronegativity?

[Liam Bertrand 3]

The easiest way to determine this is by the length of the bond. Longer bond = weaker bond. In your example, carbon-oxygen bond would be weaker because it is slightly longer than a C-N bond. There are of course other factors but this is the one that professor keeps mentioning the most, so I would assume it has the most impact.

[Jeffrey Hablewitz 2I]

Is it possible to determine the comparative length of bonds? Did you have to look up the bond lengths for C-N and C-O, or is there some way you can tell which is shorter using trends in the periodic table?