Answer:
B) an anion
Explanation:
During bonding atoms may share electron or give out electron . In the case of electrovalent or ionic bonding, electron(s) is/are transferred from one atom to another . The atom that donate the electron are known as donor atom and the atom that receives the electron are known as receivers.
The atom that donate the electron becomes a cation(positively charged) as it lose it electron(s) while the receiver gains electron to become an anion which is a negatively charge ion.
An example of such interaction is between a sodium atom and a chlorine atom. The Na atom lose it electron to become positively charged(cation) while the chlorine atom gains electron to become negatively charged(anion). Both atom bond together losing and gaining electron to fulfill the octet rule.
Na+ + Cl- → NaCl
Magnesium is divalent. This means that one magnesium atom needs to lose 2 electrons in order to become stable.
Chlorine, on the other hand, is monovalent. This means that one chlorine atom needs to gain one electron in order to become stable.
Based on this, one magnesium atom will combine with two chlorine atoms, where the magnesium loses two electrons, one for each chlorine.
The formula of the compound formed is: MgCl2
