Elements are pure chemical substances consisting of one type of atom. Elements can be metals, metalloids or non-metals. Examples: carbon, oxygen (non-metals), silicon, arsenic (metalloids), aluminium, iron, copper,...
The chemical reactions which proceed with the evolution of heat energy are called exothermic reactions. Heat evolved is expressed in Joules (J) or kilo Joules (kJ). All combustion...
The rate of a chemical reaction is defined as the change in the concentration of the reactant or product per unit time. The Factors affecting the rate of...
In a physical change, substances don’t change; only their molecules are rearranged. No new substance is formed in a physical change. In Chemical Change, a chemical reaction takes...
Atomic Number is the number of Protons in nucleus of an Atom. Mass number of an element is the number of nucleons viz. Neutrons and Protons. The atomic...
Matter can exist in at least four fundamental states viz. solid, liquid, gas and plasma. There are other states also such as Bose–Einstein condensate, quark-gluon plasmas etc. which...
Copper is a metallic element; brass is an alloy or mixture of the metallic elements copper and zinc. The surfaces of copper and brass items tamish with prolonged...
Calcium silicate (CaSiO3), a commonly used anti-caking agent, added to e.g. table salt, absorbs both water and oil. This white powder has the incredible ability to absorb liquids...
Water contains both dissolved gases (e.g., oxygen) from the atmosphere and dissolved minerals (e.g., calcium and magnesium salts). The presence of these substances affects the temperature at which...
