Units

Some substances such as sodium chloride do not contain discrete molecules as their constituent units. In such compounds, positive (sodium) and negative (chloride) entities are…

Average Atomic Mass: Many naturally occurring elements exist as more than one isotope. When we take into account the existence of these isotopes and their…

The atomic mass or the mass of an atom is actually very-very small because atoms are extremely small. Today, we have sophisticated techniques e.g., mass…

Dalton’s Atomic Theory Although the origin of idea that matter is composed of small indivisible particles’ called ‘a tomb’ (meaning —indivisible), dates back to the…

Law of Multiple Proportions was proposed by Dalton in 1803. According to this law, if two elements can combine to form more than one compound, the…

Law of Gaseous Volumes was given by Gay Lussac in 1808. He observed that when gases combine or are produced in a chemical reaction they do…

In 1811, Avogadro proposed that equal volumes of gases at the same temperature and pressure should contain equal number of molecules. Avogadro made a distinction…

While calculating, there is a need to convert units from one system to other. The method used to accomplish this is called factor label method…

Law of definite composition was given by, a French chemist, Joseph Proust. He stated that a given compound always contains exactly the same proportion of elements…

Law of Conservation of Mass states that matter can neither be created nor destroyed. The law of conservation of mass states that mass in an isolated system…