Use the following steps to balance the redox reaction below:

Mg + Au+ Mg2+ + Au

-Write the oxidation and reduction half-reactions. Make sure each half-reaction is balanced for number of atoms and charge.
-Multiply each half-reaction by the correct number, in order to balance charges for the two half-reactions.
-Add the equations and simplify to get a balanced equation

To balance the redox reaction between Mg and Au+, follow these steps:

Step 1: Write the oxidation and reduction half-reactions.
- Identify which element is being oxidized and which is being reduced.
- In this reaction:
- Mg is being oxidized from its elemental form (Mg) to Mg2+.
- Au+ is being reduced from Au+ to elemental Au.

The half-reactions are:
Oxidation: Mg -> Mg2+ (oxidation state changes from 0 to +2)
Reduction: Au+ -> Au (oxidation state changes from +1 to 0)

Step 2: Balance the number of atoms and charges in each half-reaction.
- The oxidation half-reaction is already balanced in terms of atoms, but it needs to be balanced in terms of charges.
- The reduction half-reaction has 1 Au+ on the left side, and 1 Au on the right side, so the atoms are already balanced. However, it also needs to be balanced in terms of charges.

For the oxidation half-reaction:
Mg -> Mg2+
We need to add 2 electrons (e-) to the left side to balance the charges:
Mg -> Mg2+ + 2e-

For the reduction half-reaction:
Au+ -> Au
It already has the correct number of atoms, but to balance charges, we need to add 1 electron (e-) to the left side:
Au+ + e- -> Au

Step 3: Multiply each half-reaction by the correct number, to balance charges.
The electrons should cancel out when added together. You can do this by multiplying one or both of the half-reactions by integers.

Multiplying the oxidation half-reaction by 1 and the reduction half-reaction by 2, we get:
2Au+ + 2e- -> 2Au (reduction)
2Mg -> 2Mg2+ + 4e- (oxidation)

Step 4: Add the equations and simplify to get a balanced equation.
Now, add the two half-reactions together, making sure that the electrons cancel out:
2Au+ + 2e- + 2Mg -> 2Au + 2Mg2+ + 4e-

Combine like terms:
2Au+ + 2Mg -> 2Au + 2Mg2+

Simplifying, we get the balanced redox equation:
Mg + Au+ -> Mg2+ + Au

These are far to detailed to do them justice on the web. Here is a site that explains how to balance redox equations.

http://www.chemteam.info/Redox/Redox.html

I can help a little by getting you started.
Mg changes from zero on the left to +2 on the right. Au changes from +1 on the left to zero on the right. By the way, with no arrow, how the ## do you know where the reactants stop and the products start. You don't. Learn how to make an arrow. ==> or -->