Which of the following property is generally not shown by metals (except some metals)?
Hint: Metals are lustrous.
Step 1: Metals are generally good conductors of heat and electricity, sonorous, lustrous, ductile, malleable, and have high density.
Step 2:
$$\bullet$$ Metals are generally good conductors of electricity because of the free valence electrons.
$$\bullet$$ When struck with hard objects metal produces a ringing sound. This property is called sonorous.
$$\bullet$$ Metals are shiny because metals contain free electrons that vibrate when they come in contact with light.
$$\bullet$$ Metals can be drawn into thin wire and this property of metal is called ductility.
Step 3: Metals contain free electrons that vibrate when they come in contact with light which makes them shiny. They do not appear dull. They appear dull only when exposed to air for a long time due to oxidation.
Final step: So, the correct option is (C) Dullness.
Give reasons. (a) Platinum, gold and silver are used to make jewellery. (b) Sodium, potassium and lithium are stored under oil. (c) Aluminium is a highly reactive metal, yet it is used to make utensils for cooking. (d) Carbonate and sulphide ores are usually converted into oxides during the process of extraction.
In Fig you find that the bulb glows when an iron nail is placed between two ends of wire. Complete the following sentences on the bases of this fact. __________is a metal. Metals are good_________ of electricity.
Give reasons: NaCl is not a conductor of electricity in solid state whereas is does conduct electricity in aqueous solution as well as in molten state.
____________ is the metal existing in liquid form at ordinary temperatures.
Which of the following metal does not conduct electricity?
Ornaments are usually made up of ____________ gold.
Which is the best conductor of electricity?
Which of the following is a property of non-metals?
The metal which is soft?
An element that is relatively strong is relatively: