METALS

THIS PART OF THE PROJECT IS ABOUT METALS AND

THEIR PHYSICAL PROPERTIES

METALS• A metal is an element or compound that is a good conductor of

both electricity and heat. Metals are usually malleable, ductile and shiny In a metal, atoms lose electrons to form positive ions.

IRON SILVER

ALLOY-• An alloy is a mixture of two or more elements in solid solution in

which the major component is a metal. Most pure metals are either too soft, brittle for practical use. Combining different ratios of metals as alloys modifies the properties of pure metals to produce different characteristics. The aim of making alloys is generally to make them less brittle, harder, resistant to corrosion, or have a more desirable colour and lustre.

PHYSICAL PROPERTIESTHE FOLLOWING ARE THE PHYSICAL PROPERTIES OF METALS-• Metals are malleable : Metals can be hammered or beaten into

thin sheets without breaking. Malleable means that metallic bonds in the metals do not break easily. Gold (Au), silver (Ag) are highly malleable elements. Metals can be made into thin foils because they are malleable.

• Metals are ductile : Metals can be melted and drawn into thin wires. Because of this property, metals are known as ductile. The ductility property follows from the malleability property. While being drawn into wires, metals are stretched. Because of the strong metallic bonds, the metal atoms do not separate easily. Silver (Ag), copper (Cu), aluminium (Al) are very ductile, very thin wires can be made out of these elements.

• Metals are good conductors of heat and electricity : In metals, the bonds are formed by excess or free electrons moving around large array of atoms. These electrons are able to conduct electricity and heat. Silver (Ag), copper (Cu), aluminum (Al) are good conductors of heat and electricity. Amongst metals, lead (Pb) is a poor conductor of electricity.

• Melting and boiling points : All metals, other than sodium (Na) and potassium (K), have high melting and boiling points. The melting point of iron is about 1540C.

• Metals are sonorous : Metals make a characteristic sound when hit with an object. Thus metals are sonorous. The sonorousness of metals depends on the temperature and density.  

NON-METALS

THIS PART OF THE PROJECT ISABOUT NON-METALS AND

THEIR PHYSCIAL PROPERTIES

NON-METALSNon-metals don’t have a rigorous definition. They are called non metals because they are-• dull and brittle(in physical form), rather than metals which are

lustrous, ductile or malleable• Poor conductors of heat.• usually less dense than metals.• significantly less in their melting points and boiling points than

metals (with the exception of carbon)Some non-metal elements are-• HYDROGEN (H₂)• OXYGEN (O₂)• SULPHUR (S)• PHOSPHOUROUS (P)etc.

PHYSICAL PROPERTIESTHE FOLLOWING ARE THE PHYSICAL PROPERTIES OF NON METALS-

• Non-metals are not malleable or brittle : Non-metals cannot be hammered or beaten into thin sheets without breaking. Non-metals break into pieces when hammered or stretched. Sulphur, phosphorous are powders and cannot be made into a sheet.

• Non-metals are not ductile : Non-metals cannot be melted and drawn into thin wires. The non-ductility property follows from the non-malleability or the brittleness property.

• Non-metals are bad conductors of heat and electricity : In non-metals, the bonds formed are weak as there are no free electrons to share. Other than graphite, which is an another form of carbon, none of the non-metals are good conductors of heat and electricity. Graphite is able to conduct electricity because of its special crystalline arrangement.

• Melting and boiling points : All non-metals, have low melting and boiling points. The melting point of sulphur (S) is 115C. Graphite and diamonds have high melting points, but these are exceptions in the non-metals.

• Non-metals are not sonorous : Non-metals do not make any characteristic sound when hit with an object. Thus non-metals are not sonorous.  

A PROJECT BY-

RITHESHVIII-C