[At least] Three. There could be more if string theory or the theory of branes proves to be true.
7
It has to do with how the atoms are connected. A full explanation of the details would be quite long, but basically the atoms in diamond are connected strongly in three dimensions but the atoms in graphite are connected strongly in only two dimensions.
one dimensions
In O3, also known as ozone, there are three spatial degrees of freedom because it is a molecule composed of three atoms: three oxygen atoms. Each atom can move independently in three dimensions.
2 dimensions
It has three dimensions.
it has 2 Dimensions
Space has 3 million dimensions
It has 2 dimensions which are length and width
They have positive non-integer dimensions.
A Plain Triangle Has 2 Dimensions.
Other Dimensions has 329 pages.