The mass of an element is typically represented by its atomic mass. Tin's atomic mass is 118.710 u (atomic mass units).

Here's what that means:

* Atomic mass unit (u): A unit of mass used for atoms and molecules. It's defined as 1/12 the mass of a carbon-12 atom.

* 118.710 u: This means a single tin atom is about 118.710 times heavier than 1/12 the mass of a carbon-12 atom.

Important note: While we often say an element's "mass" is its atomic mass, that's technically its average atomic mass. This is because tin has multiple isotopes (atoms of the same element with different numbers of neutrons). The atomic mass listed is the weighted average of the masses of all its naturally occurring isotopes.