TNPSC Free Notes Chemistry – Elements and Compounds Part 3

இந்தக் கட்டுரையில், TNPSC குரூப் 1, குரூப் 2, குரூப் 2A, குரூப் 4 மாநிலப் போட்டித் தேர்வுகளான TNUSRB, TRB, TET, TNEB போன்றவற்றுக்கான  முறைகள் இலவசக் குறிப்புகளைப் பெறுவீர்கள்.தேர்வுக்கு தயாராவோர் இங்குள்ள பாடக்குறிப்புகளை படித்து பயன்பெற வாழ்த்துகிறோம்.

  Elements and Compounds

Mettalloids
 Metalloids exhibit the properties of both metals and non metals.
 Boron, Silicon, Germanium, Arsenic, Antimony, Tellurium, Polonium.
Physical properties of Metalloids
 Metalloids are solids at room temperature.
 They can form alloys with other metals. Some metalloids, such as silicon and
germanium, can act as electrical conductors under specific conditions. Thus, they are
called semiconductors.

 Silicon which is a metalloid appears lustrous, but it is neither malleable nor ductile. It is
brittle – a characteristic of some non metals.
 It is a much poorer conductor of heat and electricity than the metals.
 The physical properties of metalloids tend to be metallic, but their chemical properties
tend to be non-metallic.
Uses of Metalloids
 Silicon is used in electronic devices.
 Boron is used in fireworks and as a fuel for ignition in rocket.
Compounds
 Compound is a pure substance
 Formed due to chemical combination of elements
 Definite proportions
Example
 Water – (H 2 O) Hydrogen (2) : Oxygen (1)
 Carbon di oxide, Sulphuric acid, sand, methane

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