P. 77

1. a(6) b(13) c(82) d(17)
2. a. no b. no c. yes d. no
3. C
    C
    20, 20
    Pt, 78 , 78
    92, 92
4. This is wrong because the student says that it needs to gain two protons to make the ion, but the values must be equal and we do not have enough information in order to identify if this is correct.
5. a. 12, 13, 41, 195, 238. b. Mg-25 and Mg-26

Thanks!
Forever and Always,
Abi