You are given two fatlike solid substances and determine that sample a has a higher melting point than sample
b. sample a, therefore,

Look at the spectrums of a star moving towards earth and a motionless star. which of these is a correct inference that can be draw from the observation of the two spectrums? (2 points) the spectrum of a motionless star is difficult to be viewed separately using oridinary telescopes. the spectrum of a motionless star is identical to the spectrum of a star which moves towards earth. the spectrum of a star shifts towards the red region when the star moves towards earth. the spectrum of a star shifts towards the blue region when the star moves towards earth.

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following equation:

Why is the melting of ice a physical change ?