What does mechanical digestion mean ?

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following 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.

Which electron configuration represents the electrons in an atom of sodium in the ground state at stp