Metals are the naturally occurring compounds of the earth found below the surface in the form of ores. They can be found in rocks also, and they comprise 25% of the earth's crust and are used around us in our daily lives.
Gold, silver, lead, iron and brass were also in use in the 5th millennium BCE. They are very strong and durable substances and thus used for manufacturing automobiles, satellites, cooking utensils, the framework for skyscrapers, etc. They possess properties such as malleability, and ductility and are sonorous besides being good conductors of heat and electricity.
Metal Definition Chemistry
The chemical definition of metal can is that it is highly dense, malleable and ductile and can form alloys with other metals and nonmetals, some react with air and corrode, for e.g. iron. They are good conductors of heat and electricity, for e.g. silver. Metals are solid at room temperature, except mercury is in a liquid state.
Types of Metals
Metals can be classified in a number of ways:
1. Classification by Iron Content - When a metal contains iron it is called a ferrous metal and imparts magnetic properties to a substance, metals which don't have iron content are non-ferrous metals and do not possess any magnetic properties. Examples are aluminium, brass, copper, etc.
2. Classification on the Basis of Atomic Structure - According to its placement in the Periodic table, a metal can be alkaline, alkaline earth or transition metal.
3. Magnetic and Non-Magnetic Metals - Ferromagnetic metals strongly attract magnets, paramagnetic metals exhibit weak attractions and diamagnetic metals exhibit a weak repulsion to magnets. Certain metals are most suitable for certain applications depending on their cost, safety factor, electrical conductivity, density, etc.
Metals in Periodic Table
The metals are classified in the periodic table by their placement in it. They lose electrons fairly easily but gain them with difficulty. They possess few valence electrons and can form positively charged cations.
Alkali Metals: These are found in the first column on the left side of the periodic table. They are soft, highly reactive, and possess one electron in their outer subshell, examples are lithium, sodium, potassium, and rubidium.
Alkaline Earth Metals: These have two electrons in their outermost subshell, they each make a distinctive colour with their flames. Examples are beryllium, magnesium, calcium, strontium, barium, and radium.
Transition Metals: These are found in the centre of the main periodic table, they are also called heavy metals and are denser than any other metals. There are 38 Transition Metals including cobalt, copper, gold, iron, mercury, silver, tungsten, titanium, zinc, etc. Other than them, there are inner transition (f-block) elements also.
Most of the elements in the periodic table are metals; for example iron, copper, silver, mercury, gold, nickel and tin. Around 92 of 118 elements are metals; the accuracy sometimes differs because boundaries between metals, non-metals and metalloids are blurry. Metals are good conductors of electricity and heat, they have a high melting point, and apart from being malleable and ductile, all these properties nonmetals lack. Metalloids fall between metals and non-metals in appearance and properties.
Examples of Metals
Metals are found on the left side of the periodic table, they consist of alkali metals, alkaline earth, transition metals, lanthanides and actinides. Over 75% of elements are metals and fill most of the periodic table.
Iron, zinc, titanium, aluminium, silver, gold, copper, chromium, platinum, manganese, lead, tin, cadmium, mercury, antimony, cobalt etc. are some examples of metals. Iron is present in abundance in the earth's crust, it's ductile and hard and through alloying with carbon we obtain steel. Aluminium is used amply in industrial, iron and steel trades because of its low density and good resistance to corrosion.
Metal Chemical Formula
When a metal reacts with oxygen, metallic oxide is formed. For example, magnesium reacts with oxygen to form magnesium oxide.
The chemical formula of metal oxide is MxOy.
The chemical formula for copper(I) oxide is Cu2O.
The chemical formula for aluminium bromide is AlBr3.
The chemical formula for iron(III) chloride is FeCl3.
Metals and Their Properties
Metals react with non-metals to form ionic bonds for eg. sodium chloride, metals have high melting and boiling points, they are lustrous, they are hard so are used in making buildings, ships etc.
The Eiffel tower in Paris, France is made of wrought iron.
When tin is bent to produce a particular shape it emits a peculiar sound known as a 'tin cry'.
Key Features of Metals
Metals are the naturally occurring element of the earth found below the surface in the form of ores.
Metals are lustrous and possess malleability and ductility.
Over 75% of elements are metals and fill most of the periodic table.