How many σ bonds are there in each molecule ethane ethylene acetylene?

Which phrase best describes the rock's texture? 1.jagged grains 2.coarse grains 3.rounded grains 4.non-banded grains

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.

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