This is an **oxidation-reduction** (redox) reaction:

*S0 + 2 e- → S-II (reduction)*

*Mg0 - 2 e- → MgII (oxidation)*

** S** is an

**oxidizing**agent,

**is a**

*Mg***reducing**agent.

### Word equation

*magnesium + mixed sulfur → magnesium sulfide*

### Input interpretation

*Mg + S → Mgs*

*Magnesium mixed sulfur magnesium sulfide*

### Balanced equation

Balance the chemical equation algebraically:

*Mg + S → Mgs*

Add stoichiometric coefficients, c, to the reactants and products:

*c1Mg + c2S → c3Mgs*

Set the number of atoms in the reactants equal to the number of atoms in the products for ** Mg **and

**:**

*S**Mg: c1 = c3*

*S: c2 = c3*

Since the coefficients are relative quantities and underdetermined, choose a coefficient to set arbitrarily. To keep the coefficients small, the arbitrary value is ordinarily one. For instance, set ** c1 = 1** and solve the system of equations for the remaining coefficients:

*c1 = 1 c2=1 *

*c3 = 1*

Substitute the coefficients into the chemical reaction to obtain the balanced equation:

**Answer**:

*Mg + S → Mgs*