Final answer:
The statement that magnesium can reach Group VIIIA by moving back two boxes to neon is false. A neutral magnesium atom has 12 protons, 12 electrons, and typically 12 neutrons. When forming ions, magnesium loses two electrons to become an Mg2+ cation, known as a magnesium ion.
Step-by-step explanation:
The statement that the shortest path to a Group VIIIA box from magnesium in Group IIA is to retreat two boxes to land on the neon (Ne) box is false. Magnesium is in Group 2A and has an atomic number of 12. Its position in the periodic table indicates that the nearest noble gas, neon (Ne), is actually within the same period, not two boxes away.
From magnesium, moving back one box would still place you within Group 2A (beryllium, Be), and the second move back would place you in hydrogen (H), which is not a noble gas. The nearest noble gas going backward is helium (He), located above neon (Ne), but that is not within the same period.
Regarding magnesium's atomic structure, a neutral magnesium atom has 12 protons and, therefore, must have 12 electrons to be neutral. The number of neutrons can vary depending on the isotope, but for the most common isotope of magnesium (24Mg), it has 12 neutrons. The correct statement is 'a. It has 12 protons, 12 electrons, and 12 neutrons.'
When forming ions, magnesium tends to lose two electrons to achieve a stable electron configuration similar to that of neon, the nearest noble gas. The resulting ion is the Mg2+ cation, with the symbol Mg2+ and named a magnesium ion.