Question

Q-30 (a) Silver articles turn black when kept in the open for a few days. The articles when rubbed with toothpaste
again start shining.
(i) Why do silver articles turn black when kept in the open for a few days? Name the phenomena involved.
(ii) Name the black substance formed and give its chemical formula
(b) Write the formulae of:- (i) calcium phosphate and (ii) ammonium carbonate
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Answer 1

Answer:

1.due to corrosion

2.ag2s-silver sulphide

b.1.ca3(po4)3

2.nh3cl

Answer 2

Answer:

1 due to corrosion

2 ag 2 silver sulphide

3 1ca3po43

4 nh3cl