The reactivity of copper is low because of its

high enthalpy of sublimation and high ionization energy

The correct answer is (2) high enthalpy of sublimation and high ionization energy.

Copper has a high ionization energy because it acquires a stable fully filled configuration after donating an electron. This means that it takes more energy to remove an electron from copper, which makes it less reactive.

Copper also has a high enthalpy of sublimation because of the presence of strong extensive intermolecular metallic bonds in it. These bonds are difficult to break, which makes it more difficult for copper atoms to escape from the solid state.

Finally, copper has low hydration energy. This means that it does not release a lot of energy when it is dissolved in water. This makes it less reactive, as it is not as likely to react with other substances in water.

Here is a summary of the factors that contribute to the low reactivity of copper:

High ionization energy: It takes more energy to remove an electron from copper, which makes it less reactive.

High enthalpy of sublimation: The strong intermolecular metallic bonds in copper are difficult to break, which makes it more difficult for copper atoms to escape from the solid state.

Low hydration energy: Copper does not release a lot of energy when it is dissolved in water. This makes it less likely to react with other substances in water.

As a result of these factors, copper is a relatively non-reactive element. It does not react easily with other elements, and it is not easily dissolved in water. This makes it a useful material for a variety of applications, such as electrical wiring and jewelry.