The half life of Tc-99 (used for curing brain tumors) is 6 hours. If 10 micrograms are left after 24 hours, how much was administered to the patient originally? please please please please please help i will give brainliest to the best answer!

Compared with the freezing-point depression of a 0.01 m c6h12o6 solution, the freezing-point depression of a 0.01 m nacl solution is

List four observations that indicate that a chemical reaction may be taking place

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.