An unknown element is found with the following isotopic percent abundance: X-20 is found at an abundance of 90.50%, X-21 is found at an abundance of .27%, and X-22 is found at an abundance of 9.23%. Given this information find the average atomic mass of the element. (show your work for full credit.)

Using the periodic table, complete the table to describe each atom. type in your answers

What is the ph of a 0.0010 m hno3? 1.0 3.0 4.0 5.0

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.