Solid butter or margarine might have air in it, so the amount you get into a cup is somewhat less than when you melt it and it compresses. This means you have more in a cup and it will weigh more. Always check if a recipe calls for butter or margarine to be melted before you measure it or you may have the wrong amount.
All other things being equal, a solid material will be denser than a liquid material when the materials are similar, or almost identical.
Because there may be a little air in butter as a solid form
It depends on the recipe. Shortening becomes solid at room temperature while vegetable oil does not. So vegetable oil may be substituted for melted shortening only in recipes that do not depend on shortening becoming solid for texture when cooled.
I normally replace with half shortening and half butter. It works fine.
You can safely substitute liquid oil for solid shortening in baking ONLY if the recipe calls for the shortening to be melted first. You can substitute butter or margarine for shortening ( 1 cup + 2 Tbsp for each cup of shortening). You can also substitute 1/2 cup applesauce or prune puree for each cup of shortening.
he melted
A measureing cup
Rice Krispies Treats
yes
yes as it is plastic
Yes, melted shortening can replace vegetable oil in zucchini bread, although shortening is not a healthy choice.
Yes, melted plastic can hurt you. The primary danger is from a burn. Melted plastic is hot, and it tends to stick to skin and clothing. It is exceptionally dangerous stuff in that regard.
Plastic is always going to be plastic. When plastic is melted it becomes hard.