To find the correct formula of the compound formed when magnesium (Mg) reacts with chlorine (Cl), we need to consider the typical charges of the ions that these elements form.
1. Magnesium (Mg) Properties:
- Magnesium is an alkaline earth metal located in Group 2 of the periodic table.
- Magnesium typically loses two electrons to achieve a stable noble gas electron configuration. By losing two electrons, magnesium forms a \( \text{Mg}^{2+} \) ion.
2. Chlorine (Cl) Properties:
- Chlorine is a halogen located in Group 17 of the periodic table.
- Chlorine typically gains one electron to achieve a stable noble gas electron configuration. By gaining one electron, chlorine forms a \( \text{Cl}^- \) ion.
3. Forming the Ionic Compound:
- To form a neutral compound, the total positive charge must balance the total negative charge.
- Since the \( \text{Mg}^{2+} \) ion has a charge of +2 and each \( \text{Cl}^- \) ion has a charge of -1, we need two \( \text{Cl}^- \) ions to balance one \( \text{Mg}^{2+} \) ion.
4. Combining the Ions:
- One \( \text{Mg}^{2+} \) ion will pair with two \( \text{Cl}^- \) ions.
- The resulting chemical formula reflects the ratio of magnesium to chlorine needed for charge balance: \( MgCl_2 \).
Therefore, the correct formula of the compound formed is \( MgCl_2 \).
By examining the given options:
1. \( MgCl_2 \)
2. \( Cl_2 Mg \)
3. \( Cl_2 Mg_2 \)
4. \( Mg^{2-} Cl_2^- \)
The first option, \( MgCl_2 \), accurately represents the ionic compound formed when magnesium and chlorine react. Thus, the correct answer is:
[tex]\[ MgCl_2 \][/tex]
