A sample of silver metal contains 1.91 X 1021 atoms. How many moles of silver is
this?

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.

The chemical bond connecting one nucleotide with the next one along the nucleic acid chain is called a

What is the area in square meters of 448 g ai foil that has a thickness of 23921 nm? the density is 2.70 g/cm