What are duplet and octet elements ?Differentiate.

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 reactions of photosynthesis occur in the of plant cell? a.mitochondria. b. lysosomes. c. chloroplasts. d. chlorophyll

An atom with 7 protons, 6 neutrons, and 7 electrons has an atomic mass of amu. (enter a whole number.) numerical answers expected! answer for blank 1: