Science Do As Directed.

True or False : The reactivity of metals increase down to reactivity series.

True or False : The process of separating gangue from the ores is called concentration of ores.

True or False : The process of converting sulphide ores into oxides by heating strongly in excess of air is called Calcination.

True or False : The minerals from which the metal can be separated economically are called ores.

True or False : The elements or compounds which occur naturally is earth's crust are known as minerals.

True or False : Stannic oxide (SnO₂) is a magnetic and Ferrous tungstate (FeWO₄) is a non-magnetic ingredient.

True or False : Silver plated spoon, gold plated ornaments are the examples of alloying.

True or False : silver amalgam is mainly used by dentists.

True or False : Ore contains some impurities, these are called gangue.

True or False : Non - metals react with acids to give a salt and hydrogen gas.

True or False : Non-metals combine with oxygen to form basic oxides.

True or False : Non - metals are good conductors of heat and electricity.

True or False : Nitric acid is a strong oxidizing agent.

True or False : Metals gain electrons and become negatively charged ions.

True or False : Metals are known as sonar metals.

True or False : Metallic iron is more reactive than metallic copper.

True or False : Mercury, silver and gold are very reactive metals.

True or False : Ionic compounds in the solid state conduct electricity.

True or False : Ionic compounds have low melting points.

True or False : Ionic compounds have low melting points.

True or False : Ionic compounds are soluble in kerosene.

True or False : Iodine is a lustrous metal.

True or False : Iodine and diamond are lustrous substances.

True or False : In the process of 'Kalhaee' a metal is coated with Zinc to prevent its corrosion.

True or False : In electroplating a metal is coated with another metal using electrolysis.

True or False : In anodising method. the copper or aluminium article is used as anode.

True or False : If one of the metals in an alloy is mercury then it is known as Amalgam.

True or False : Electronic configuration of Aluminium is 2,8,2.

True or False : Electrolysis method is used to obtain pure metals from impure metals.

True or False : Electrolysis is the method used to obtain pure metals from impure metals.

True or False : Due to corrosion a greenish layer forms on the surface of copper or brass vessel.

True or False : Diamond is the softest natural substance.

True or False : Cryolite (Na₃ AlF₆) and Fluorspar (CaF₂) are used to increase the melting point of alumina.

True or False : Corrosion of metals can be stopped by detaching the air from metals.

True or False : Corrosion is degradation of a reaction with its environment.

True or False : copper reacts with moist carbon form copper carbonate.

True or False : Aluminium oxide is an acidic oxide.

True or False : Alloys are resistant to corrosion.

True or False : Alloys are resistant to corrosion.

Water, Ammonia, Sodium chloride, Hydrogen chloride.

Steel, Iron, Copper, Tungsten

Sodium oxide, Zinc oxide, Potassium oxide, magnesium oxide.

Silver, Gold, Platinum, Calcium

Malleability, Ductility, Brittleness, Lustre.

K₂O, Na₂O, CaO, Al₂O₃

Graphite, Iodine, Silver, Phosphorous.

Galvanizing, Tinning, Anodizing, Roasting

Copper, Gallium, Gold, Silver.

Brass, Bronze, Steel, Antimony