Give the reason why the empty crucible should be heated before starting the experiment

Which solution is an example of a nonelectrolyte? a. iodine in hexane b. sodium nitrate in waterc. acetic acid in waterd. hydrogen chloride in water

The peak wavelength for the blackbody curve of a star is in the uv range. assuming the radiation from this star can reach earth, would you be able to see it?

If you burn 10 kilograms of wood in a fire (combustion) what is the weight of the products after the fire has finished burning the wood?