Brainliest if answered in the next 5 minutes

energy is required to start a reaction.

kinetic
potential
nuclear
activation

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.

In salt water solution,the salt is the blank

No copying 15 pts how does a free-body diagram tell you about the net force on an object?