Na2B4O7-10H2O does not represent an element or a single compound on the periodic table. It is the chemical formula for borax decahydrate, a compound that is commonly known as borax.

Here's the breakdown of the formula:

* Na: Represents the element sodium

* 2: Indicates there are two sodium atoms in the molecule

* B: Represents the element boron

* 4: Indicates there are four boron atoms in the molecule

* O: Represents the element oxygen

* 7: Indicates there are seven oxygen atoms in the molecule

* -10H2O: Indicates that ten water molecules are associated with the borax molecule, forming a hydrate.

Therefore, Na2B4O7-10H2O stands for borax decahydrate, a compound that contains sodium, boron, oxygen, and water molecules.