Question

Q.2. Give reasons for the following. l) Bells used in temples are made of metals and not wood. 2) A copper vessel when exposed to moist air for long acquires a dull green coating. Sodium metal is kept stored in kerosene. ) Phosphorus is kept stored in 'Gold and Silver are

Answer 1

Dear student,

6) More, less
7) Metalloids
8) Chlorine
9) Bromine

Q2. 1. Metals are sonorous that is they produce a ringing sound when struck hard This property is absent in non metals. Non metals are generally not hard as metals. Bells are thus made of metals .

2. This green coating is a mixture of (i) copper hydroxide and (ii) copper carbonate.The reaction is as follows:

2Cu + H₂O + CO₂ + O₂ → Cu(OH)₂ + CuCO₃

3.Sodium is a very reactive metal and reacts with water to form hydrogen gas and sodium hydroxide. The reaction is highly exothermic i.e. a lot of heat is produced .The hydrogen gas catches fire and cause explosions. Thus it is kept under kerosene(hydrocarbon) as it doesn’t react with hydrocarbon.

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