With reference to 'Silver articles', which of the following statements is/are correct ?
1. Silver articles turn black after some time when exposed to air.
2. It happens due to coating of silver sulphide.
Select the correct answer from the code given below :
Code :

Both statements are correct. Silver is a relatively unreactive metal, but it reacts with sulphur compounds (such as hydrogen sulphide, H2S) present in the atmosphere. This chemical reaction leads to the formation of a thin black layer of silver sulphide (Ag2S) on the surface of the article. This process is commonly known as tarnishing. The reaction can be represented as: 4Ag + 2H2S + O2 → 2Ag2S + 2H2O. While oxygen is required for the reaction to proceed at room temperature, it is the sulphur that causes the specific black discolouration. Therefore, silver articles lose their shine and turn black when exposed to air over time due to the accumulation of silver sulphide.