Basic chem:
1. fes2 + o2 --> fe2o3 + so2
balanced equation:
2. al + o2 --> alo2
balanced equation:
3. k + br2 --> kbr
balanced equation:
4. sio2 + hf --> sif4 + h2o
balanced equation:

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.