Why are fossil fuels a rich source of energy? fossil fuels require activation energy to burn
heat is released when fossil fuels combine with oxygen
fossil fuels are millions of years old
carbon dioxide is released when fossil fuels combine with oxygen

How did planetesmals form planets? a. they broke apart into smaller chunks.b. they collided and stuck together.c. they cooled and pulled ice together.d. they began to rotate.

The grooves or folds of the brain are called

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.