)is it possible for one component of a vector to be zero, while the vector itself is not zero?

The least number of component of a vector quantity is two. These are the x-component and the y-component. 

The resultant vector, or vector as we refer to it in this item, can be calculated through the equation,
              RV = sqrt ((Vx)² + (Vy)²)

From the equation, it can be noted that if we let Vx equal to zero,
              RV = Vy

Similarly, if we let Vy be equal to zero then,
             RV = Vx

Thus, it is still possible for the vector to become nonzero even if one of its components is zero.