a silver object turns black when kept in pen for a long time. why?

Q. Why silver turns into black after a long time? Give the reason.

Q. A silver article generally turns black when kept in the open for a few days. The article when rubbed with toothpaste again starts shining. Silver articles turn black when kept in the open for a few days because of _________.

Q.

Question 38

A silver article generally turns black when kept in the open for a few days. The article when rubbed with toothpaste again starts shining.

(a) Why do silver articles turn black when kept in the open for a few days? Name the phenomenon involved.

(b) Name the black substance formed and give its chemical formula.

Q. Explain why [4 MARKS]
(a) Only all-glass apparatus should be used for the preparation of nitric acid by heating concentrated sulphuric acid and potassium nitrate.
(b) Nitric acid, when kept in a reagent bottle for a long time, turns yellow.

Q. Why do silver articles turn black when kept open for a few days?
(a) Name the phenomenon involved.
(b) Name the black substance formed and give its chemical formula.