Ornaments are usually made up of ____________ gold.
Ornaments made from 24-carat gold are very rare since pure gold is very soft and is prone to wear and tear upon usage. Hence 22-carat gold is generally used which contains a slight amount of copper, silver and other metals in order to impart wear resistance and at the same time retain its elegance
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.
Which of the following property is generally not shown by metals (except some metals)?
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?
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: