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0.05 cm thick coating of silver is deposited on a plate of 0.05 m2 area. The number of silver atoms deposited on plate are 1023. (At mass Ag = 108, d = 7.9 g cm-3)
11
Area = 0.05 m2 = 0.05 104 cm2 = 500 cm2
Volume = 500 × 0.05 = 25 cm3 ⇒ mass = 25 × 7.9 = 197.5 g
Atoms = 197.5108 6.022 1023
= 1.829 6.022 1023
= 11.01 1023 ≈ 11 1023
Answer: 11
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