History of AluminiumSymbolAlAtomic number13 HistoryAluminium was first extracted in 1827 from aluminium chloride by treating it with sodium : AlCl3 + 3Na  →  Al + 3NaCl.But the process was very expensive. Impressed by its properties, metallurgists all ov…

How many Allotropes of Carbon are thereThe property of an element to exist in two or more physical forms having more or less similar chemical properties but different physical properties is called allotropy. The different forms of the element are called …

How metal is formed in the EarthMetals occur in nature in free state or in combined state. A metal is said to occur native or free when it is found in nature in the metallic state. For example, gold may be found in nature as metal. This is because gold …

What Is Valence or Valency in ChemistryValency The combining capacity of an element is known as its valency. Formulae and valencies of common ionsElectropositive Ions MonovalentBivalent NameFormulaNameFormulaPotassium K+BariumBa2+SodiumNa+CalciumCa2+Cop…

What is Sublimation in chemistrySublimation : The changing of a solid directly into vapours on heating, and of vapours into solid on cooling, is known as sublimation. Sublimation can be represented as: The solid substance which undergoes sublimation is …

What is a Chemical Change and give some ExamplesChemical change A chemical change (also called chemical reaction) occurs when two or more chemical substances react to produce a new substance (or substances) with a different set of properties. A chemical …

Applications of exothermic and endothermic reactions in everyday life Application of exothermic and endothermic reactions: The principle of exothermic and endothermic reactions is applied in instant cold packs and hot packs which are used to treat sports…

What are the Problems with the Use of Fossil FuelsLimitations of Fossil FuelsScientists at Sandia National Laboratories, New Mexico, have succeeded in producing fuels like petrol and methanol using sunlight and carbon dioxide. The two main limitations of…

Properties and Uses of Ethanoic AcidEthanoic acid (Acetic acid) CH3COOH : Ethanoic acid is most commonly known as acetic acid. Its dilute solution in water (5-8%) is known as vinegar, which is used for preserving food-sausage, pickles etc. Physical prop…

What are the Different Types of Fuels and Their CharacteristicsFuelsMost of the substances used for burning are fuels. Substances that produce heat and light energy on burning are called fuels. Some commonly used fuels are wood, coal, cow dung cakes, ke…