Scheele discovered chlorine in 1774 by the action of HCl on MnO2. The gaseous element itself was first produced in 1774 by Carl Wilhelm Scheele... View Article
Since the outermost orbital contains only two electrons, alkaline earth metals show divalency by losing these two electrons. All alkaline earth... View Article
Aldehydes and ketones have Carbonyl group (C=O) in common. In a ketone, two carbon groups are attached to the carbonyl carbon atom. In an... View Article
The value of 'g' is minimum at the equator because earth is not a perfect sphere. Its radius is maximum at the equator. Hence, according to the... View Article
Valency is a combining capacity of an element. As there are no free electrons in the valence shell and the elements are already in a stable... View Article
The atomic size increases from top to bottom in a group because new shells are being added as we go down the group. In general, for the main... View Article
Ice floats on water because the density of ice (0.917 g cm-3) is less than water (1 gm-3). The molecules in water are affected by a phenomenon... View Article
Aqua regia is a concentrated mixture of nitric and hydrochloric acids. Aqua regia can dissolve gold and platinum. These metals do not react even... View Article
Bread mould is a spore-producing plant. Spores are reproductive cells in plants, algae and other protists; and fungi. They are typically... View Article
Cryolite is the chief ore of aluminium. Ore is defined as an economic concentration of minerals. The earthy substance associated with ores is... View Article
Manioc is the staple food of Amazon. It is one of the main constituents of the diet of people living in amazons. It is rich in carbohydrates.... View Article
Black soil is also known as regular soil. The soil comprises various amounts of vital nutrients necessary for cultivation. The soil is the top... View Article
Thigmotropism is the curvature movement of a plant in response to a unilateral touch stimulus and can be observed in many climbers. In tendril... View Article
The rays of light converge when they pass through the drops of water. Thus, the drop of water behaves like a convex lens. A water drop in the... View Article
Answer: A substance is a matter that has definite properties and composition. Every pure compound and element is a substance. Water, H2O, is a... View Article
An inclined plane is a flat supporting surface tilted at an angle, with one end higher than the other, used as an aid for raising or lowering a... View Article
The mass per unit volume of a substance is called density (density = mass/volume). As the volume of a substance increases, its density decreases.... View Article
The colour of KMnO4 is due to charge transfer transitions by absorption of visible light. KMnO4 has a deep purple colour. The metal ions in... View Article
The corrosion of the lead surface is responsible for it losing its lustre. The metals lose their shine on brightness on keeping in the air for a... View Article