Which is heavier: 1kg of flour or 1kg of steel?
A kilogram (kg) is a unit of weight, so it doesn't matter what material is being weighed - a kilogram will always be equal to a kilogram. Therefore, both weigh the same.
Instruction: Which is heavier: 1kg of flour or 1kg of steel?
Context: 
Response: A kilogram (kg) is a unit of weight, so it doesn't matter what material is being weighed - a kilogram will always be equal to a kilogram. Therefore, both weigh the same.