What is the weight of a 3.5 inch floppy disk and was the weight ever standardized?
For the sake of information available on the internet (as I wasn't able to find the answer elsewhere) I have just measured the weight of 306 3.5-inch floppy disks from several random brands. The measurement did not take into account that some floppy disks had paper labels pasted on it, while most had not.
The result: One 3.5-inch floppy disk weighs between 17-22 grams. The average weight of one 3.5-inch floppy disk is 19 grams.
Regarding the standardization: I could not find any information that indicates there has been a standardized weight for 3.5-inch floppy disks.