The power of a lens is $+2.0\text{D}$. The focal length of the lens and its nature are:

The formula relating the refractive power of a lens ($P$) to its focal length ($f$ measured in meters) is given by:
$$P=\frac{1}{f}$$

Substituting the value $P=+2.0\text{D}$:

$$f=\frac{1}{+2.0}=+0.5\text{m}=+50\text{cm}$$

Because the numeric sign of both the lens power and the resulting focal length is positive ($+$), the physical nature of the lens is convex (converging).