5. Base your answer to the question on the particle diagrams below, which show atoms and/or molecules in three different
samples of matter at STP.
Key
atom of x
atom of y
O atom of z
30
Sample 1 Sample 2 Sample 3
Which sample represents a pure substance?
1. Sample 1
2. Sample 2
3. Sample 3

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.