With reference to the divergence, which of the following statement is WRONG?

Divergence:

• Divergence is a vector operator that operates on a vector field, producing a scalar field giving the quantity of the vector field's source at each point.
• The divergence operation can be represented by a del operator (∇).
• The divergence applied on a scalar produces zero, thus it has no meaning.
• The expressions for divergence in different coordinate systems are different.

Case 1: Cartesian coordinate system (x, y, z)

Case 2: Cylindrical coordinate system (ρ, ϕ, z)

Case 3: Spherical coordinate system (r, θ, ϕ)