In a single-replacement reaction between magnesium and silver nitrate, magnesium replaces silver in the compound, leading to the formation of magnesium nitrate and elemental silver. The products of this reaction are:

Magnesium Nitrate (Mg(NO3)2): This is a water-soluble compound that exists as colourless crystals. It is the magnesium salt of nitric acid and contains magnesium ions (Mg2+) and nitrate ions (NO3-).

Elemental Silver (Ag): Elemental silver is formed as a solid, lustrous, and silvery-white metal. It is a precious metal highly valued for its unique properties, such as high electrical and thermal conductivity, malleability, and ductility.

Here's the balanced chemical equation for this reaction:

```

Mg (s) + 2AgNO3 (aq) → Mg(NO3)2 (aq) + 2Ag (s)

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In this reaction, magnesium atoms lose two electrons to become magnesium ions (Mg2+), while silver ions (Ag+) in silver nitrate gain one electron each to become elemental silver atoms (Ag). As a result, magnesium nitrate and elemental silver are formed.