Here in this article, we are discussing a new topic Metals and Non- Metals. This topic is important from Science section of CTET Paper – 2. Elements may be classified as either metals or nonmetals, based on their properties. Here’s a look at the differences between the metals and nonmetals.
Most elements are metals. On the periodic table, metals are separated from nonmetals by a zig-zag line stepping through carbon, phosphorus, selenium, iodine and radon. These elements and those to the right of them are nonmetals. Elements just to the left of the line may be termed metalloids or semimetals and have properties intermediate between those of the metals and nonmetals.
Non – Metals
Non-metals are the elements in groups 14-16 of the periodic table. Non-metals are not able to conduct electricity or heat very well. As opposed to metals, non-metallic elements are very brittle, and cannot be rolled into wires or pounded into sheets. The non-metals exist in two of the three states of matter at room temperature: gases (such as oxygen) and solids (such as carbon). The non-metals have no metallic luster, and do not reflect light. They have oxidation numbers of ±4, -3, and -2.
The physical and chemical properties of the metals and nonmetals:
Metal Physical Properties:
• lustrous (shiny)
• good conductors of heat and electricity
• high melting point
• high density (heavy for their size)
• malleable (can be hammered)
• ductile (can be drawn into wires)
• usually solid at room temperature (an exception is mercury)
• opaque as a thin sheet (can’t see through metals)
• metals are sonorous or make a bell-like sound when struck
Nonmetal Physical Properties
• not lustrous (dull appearance)
• poor conductors of heat and electricity
• non-ductile solids
• brittle solids
• may be solids, liquids or gases at room temperature
• transparent as a thin sheet
• nonmetals are not sonorous
Metal Chemical Properties
• have 1-3 electrons in the outer shell of each metal atom • corrode easily (e.g., damaged by oxidation such as tarnish or rust)
• lose electrons easily
• form oxides that are basic
• have lower electro-negativities
• are good reducing agents
Nonmetal Chemical Properties
• usually have 4-8 electrons in their outer shell
• readily gain or share valence electrons
• form oxides that are acidic
• have higher electro-negativities
• are good oxidizing agents
• Metallurgy is science of extraction of metals from their ores and their purification.
• Minerals are naturally occurring substances containing one or more elements or their compounds.
• Ore is a mineral from which one or more metals can be extracted profitably.
• Metallurgical processes:- It consists of three main steps. They are :-i) Concentration of the ore ii) Reduction iii) Refining
• Concentration of the ore:- It is the removal of impurities from the ore.
• Reduction:- it the process of obtaining the metal from its compound.
•Refining:- is the process of purification of the impure metals to obtain the pure metal.
Uses of metals:-
Iron :-is used for making pins, nails, nuts, bolts, tools, machines, construction of buildings, bridges etc.
Aluminium :-is used for making utensils, wires, furniture, parts of aircrafts, vehicles, machines, for packing food and medicines etc.
Copper:-is used for making wires, vessels, electric gadgets etc.
Gold:-is used for making jewellery, coins medals etc
Silver:-is used for making jewellery, Coins, medals etc.
Platinum:-is used for making jewellery, electric gadgets, plugs in vehicles etc.
Sodium:-compounds are used as common salt, chemicals etc.
Calcium:-compounds are used for making cement, glass etc.
Uses of non-metals:-
Sulfur:- Is used for making sulphuric acid, salts of metals etc.
Oxygen:- is used for respiration by living things, burning of fuels etc.
Nitrogen:- is used for making ammonia which is used for making fertilizers.
Hydrogen:- is used for making ammonia which is used for making fertilizers, as fuel in rockets, for welding etc.
Chlorine:- is used to kill germs in water.
Iodine:- is used as tincture iodine which is an antiseptic