The answer is C: L Group.
Answer:
I'm pretty sure its C. limestone.
Mass number= atomic number + number of neutrons.
A=Z+N
Z=number of protons=12
N=12
A=12+12=24
If, we have 12 protons and 10 electrons, the charge of this ion is +2
Therefore: mass number:24; charge: +2
Answer: a. mass number: 24; charge: +2
Iron has magnetic properties, so you would just need to hold a magnet over the mixture and the filings will come right out.