In a displacement chemical reaction, a more reactive metal can replace a less reactive metal. This phenomenon occurs due to the difference in reactivity between the two metals involved in the reaction. The reactivity of a metal is determined by its ability to lose electrons and form positive ions. Metals that readily lose electrons and form positive ions are considered more reactive, while those that do not lose electrons as easily are considered less reactive.

Displacement reactions involve the exchange of ions between two compounds. When a more reactive metal is added to a solution containing a less reactive metal, the more reactive metal will replace the less reactive metal in the compound, resulting in the formation of a new compound. This is because the more reactive metal has a greater tendency to lose electrons and form positive ions, which allows it to replace the less reactive metal in the compound.

For example, if we consider the reaction between zinc (Zn) and copper sulfate (CuSO4), zinc is more reactive than copper. When zinc is added to a solution of copper sulfate, a displacement reaction occurs. The zinc atoms lose electrons and form zinc ions (Zn2+), while the copper ions (Cu2+) in the copper sulfate solution gain electrons and form copper atoms, which then precipitate out. The resulting compound is zinc sulfate (ZnSO4).

The reactivity series of metals can be used to predict the outcome of displacement reactions. This series ranks metals from most reactive to least reactive. Metals higher in the series can displace metals lower in the series from their compounds. For example, magnesium (Mg) can displace zinc (Zn) from zinc sulfate (ZnSO4) because magnesium is more reactive than zinc.

The reactivity series of metals is as follows:

- Potassium (K)
- Sodium (Na)
- Calcium (Ca)
- Magnesium (Mg)
- Aluminum (Al)
- Zinc (Zn)
- Iron (Fe)
- Tin (Sn)
- Lead (Pb)
- Hydrogen (H)
- Copper (Cu)
- Silver (Ag)
- Gold (Au)

In conclusion, in a displacement chemical reaction, a more reactive metal can replace a less reactive metal in a compound. The reactivity of metals is determined by their ability to lose electrons and form positive ions. The reactivity series of metals can be used to predict the outcome of displacement reactions.

More reactive metal replaces less reactive metal.