Chromium-51 is a radioactive isotope used to label red blood cells to identify if they remain intact in the body. it has a half-life of 27.7 days. if 0.25 mg is an approximate dose amount, how much remains after 83.1 days?

16. why must the number of electrons lost equal the number of electrons gained in every redox reaction? use 3 – 4 sentences in your own words to address this question. 18. what type of radiation is emitted when chromium-51 decays into manganese-51? show the nuclear equation that leads you to this answer. 19. a radioactive nucleus alpha decays to yield a sodium-24 nucleus in 14.8 hours. what was the identity of the original nucleus? show the nuclear equation that leads you to this answer.

Calculate the percent composition by mass of each element in al(oh)3. use at least three significant figures.

What element has similar physical and chemical properties as boron.