Why do soilds have a fixed shape while liquids and gas do not

Aregular polygon has angkes of size 150° each.how many side has the polygon

Although longitudinal waves can travel through all media types what is the disadvantage of this type of wave transmission? a) he efficiency of he wave transmission is greatly diminished as the media becomes less dense b) the oscillation of one set of particles has a huge impact on neighboring particles c) particles become too close together as they bump into each other making it more likely to hit other particles down the line

Give one example to show that when substances are mixed,it may result in a chemical or a physical change depending on the conditions.