The following is a common misconception by students.
Remember: Weight and mass are different things.
Weight is the effect of the pull of gravity on an object. It is the same as the gravitational force acting on an object. i.e. weight is a force.
Mass is the amount of matter of an object.
The more massive, the more matter it has. On Earth, where the gravitational force is almost constant, it is easy to assume mass = weight, but remember that mass is constant no matter where the object is (in space, or on the moon).
The proper unit for weight is “N” or “Newtons”. The unit for mass is “kg”. from Study Room http://ift.tt/2gu8Hl6