**Observations**
The next day, Justin would observe that the color of the copper strip has changed to grey.

**Explanation**
When a strip of copper is placed in a beaker containing zinc sulphate solution, a redox reaction occurs between the copper and the zinc sulphate. The reaction can be represented by the following equation:

Cu (copper) + ZnSO4 (zinc sulphate) → CuSO4 (copper sulphate) + Zn (zinc)

During the reaction, the copper atoms lose electrons to form copper ions, which then go into the solution. At the same time, zinc ions from the zinc sulphate gain these electrons to form zinc atoms, which get deposited on the copper strip.

**Electrochemical Reaction**
The redox reaction that takes place is an electrochemical reaction. The copper strip serves as the anode, where oxidation occurs, and the zinc ions act as the cathode, where reduction takes place.

**Oxidation of Copper**
As copper atoms lose electrons, they are oxidized. This oxidation causes a change in the color of the copper strip from its original reddish-brown color to a greyish color. This grey color indicates the presence of copper ions in the solution.

**Deposition of Zinc**
The zinc ions in the solution gain the electrons lost by the copper atoms and get reduced to form zinc atoms. These zinc atoms then get deposited on the surface of the copper strip. The grey-colored deposits on the copper strip are actually made up of these zinc atoms.

**No Dissolution of Copper**
Contrary to the second option, the copper strip does not dissolve into the solution. Instead, the copper atoms lose electrons and form copper ions that go into the solution. The copper strip itself remains intact, but its color changes due to the formation of copper ions and the deposition of zinc atoms.

**No Color Change if No Reaction Occurs**
If no reaction occurs between the copper strip and the zinc sulphate solution, there would be no color change observed. The copper strip would retain its original reddish-brown color, indicating that no oxidation or reduction has taken place.