* Copper is less reactive than calcium: Copper is lower than calcium in the reactivity series of metals. This means copper is less likely to displace calcium from its compound.
* Limewater is a weak base: While limewater is a base, it's not a strong enough base to react with copper.
What might happen:
* No visible reaction: The most likely outcome is that you'll see no visible reaction. The copper will remain unchanged, and the limewater will retain its milky appearance.
* Slight surface oxidation: Over a very long time, you might see some very slight surface oxidation on the copper, but this is more due to the presence of oxygen in the air than the limewater itself.
In summary: Copper and limewater are generally unreactive with each other.
