How to do molar mass of compounds

One student said that the investigation was not valid (a fair test). write a plan for the investigation that includes improvements to the method and apparatus

An engineer decides to use a slightly weaker material rather than a stronger material, since she knows that the stronger material can break suddenly. this is an example of what? a choosing a material that will show warning before it fails b using composite materials that combine strength c using a material for multiple applications d using design techniques that increase efficiency and reduce cost

What properties would have caused early researchers to name hydrogen "inflammable air”