Answer: The correct answer is Option 2.
Explanation:
Malleability is the property shown by metals in which they can be flattened into thin sheets.
Metals are the elements which can easily loose its electrons to attain stability.
Electronic configurations of the given elements:
1. Chlorine: [tex]1s^22s^22p^63s^22p^5[/tex]
This element can easily gain 1 electron and hence it is considered as a non-metal.
2. Copper: [tex][Ar]3d^{10}4s^1[/tex]
This element can easily loose 1 electron and hence it is considered as a metal.
3. Helium: [tex]1s^2[/tex]
This element has fully filled configuration. It is known as a non-reactive element and is considered as a noble gas.
4. Sulfur: [tex]1s^22s^22p^63s^22p^4[/tex]
This element can easily gain 2 electrons and hence it is considered as a non-metal.
From the above information, it is clearly visible that copper is the only metal and it shows the property of malleability at STP.
Hence, the correct answer is Option 2.
