Dear Student,

In the International System of Units (SI) ,the unit of thermal conductivity is W/mK because thermal conductivity coefficient k is measured in watts per meter Kelvin (or degree) (W/mK) and coefficient  k also depends on the temperature, physical properties of the material, water content, and the pressure on the material.

Hello there,
The unit thermal conductivity is coefficient k.
It depends on:
temperature
physical properties of the material
water content
The pressure on the material
The coefficient k is measured in watts per meter Kelvin (W/mK).
Hope this helps you

In the International System of Units (SI), thermal conductivity is measured in watts per meter-kelvin. The dimension of thermal conductivity is expressed in terms of the dimensions mass (M), length (L), time (T), and temperature (Θ).

Hope it helps!

Good luck