Ruler.
This is not true. Scientists measure the density of anything they come across. Perhaps you are confused by the fact that it is easily possible to measure the volume of objects denser than water by dropping them in and measuring how the volume of liquid appears to go up. It's much more fiddly to measure the volume of objects which are less dense than water and so float in it.
They can easily go through objects
These are electrically positive objects.
Positive objects.
what is the measure of how easily a substance will burn or combine
Styrofoam
by sticking to objects
Yes, Being skeptical is helpful. Because it tells how original are you. You can't be easily persuade.
transparent ones
lubricant!
All objects resist changes in their state of motion
Measure of its chemical reactivity.