In the mid-1850s, James Young succeeded in distilling paraffin wax from coal and oil shales at Bathgate in West Lothian and developed a commercially viable method of production. The Paraffin wax was processed by distilling residue left after crude petroleum was refined. Paraffin could be used to make inexpensive candles of high quality. It was a bluish-white wax, burned cleanly, and left no unpleasant odour, unlike tallow candles. A drawback to the substance was that early coal- and petroleum-derived paraffin waxes had a very low melting point. The introduction of stearin, discovered by Michel Eugène Chevreul, solved this problem. Stearin is hard and durable, with a convenient melting range of 54–72.5 °C (129.2–162.5 °F). By the end of the 19th century, most candles being manufactured consisted of paraffin and stearic acid.

Like many other things, milk contains bacteria, Milk also naturally contains a kind of sugar known as “lactose.” The bacteria that live in milk get energy from this special sugar and use it to reproduce to make even more bacteria. When the bacteria use the lactose sugars to reproduce, they change it from “lactose sugar” into “lactic acid,” which tastes sour.

All acids contain hydrogen atom (s). In aqueons state, they produce hydrogen ions. Dilute acids react with some metals that are more electro positive than hydrogen such as Sodium, Potassium, Calcium, iron, etc to form salts. Sodium replaces two hydrogen atoms from Sulfuric acid (H2SO4) to form a normal salt, Sodium Sulphate (Na2SO4). If only one atom of hydrogen is replaced by sodium, it forms an acid salt, Sodium Hydrogen Sulphate (NaHSO4).

Acharya Sir Prafulla Chandra Ray (1861 – 1944) had established first Indian research school in chemistry and is regarded as the father of chemical science in India. He was the founder of Bengal Chemicals & Pharmaceuticals, India’s first pharmaceutical company. He also wrote a book titled “A History of Hindu Chemistry from the Earliest Times to the Middle of Sixteenth Century” , published in 1902.

Scottish physician Joseph Black is attributed with the discovery of magnesium, latent heat, specific heat, and carbon dioxide. He found that limestone (calcium carbonate) could be heated or treated with acids to yield a gas he called “fixed air.” This fixed air was denser than air and supported neither flame nor animal life. He also found out that when bubbled through limewater, it would precipitate calcium carbonate. He concluded that fixed air is produced by animal respiration and microbial fermentation.

Most of soda’s acidity also comes from phosphoric acid. Phosphoric acid is made from the mineral phosphorus, which is found naturally in the body. Phosphoric acid gives soft drinks a tangy flavor and prevents the growth of mold and bacteria.

Sir Humphry Davy (1778 – 1829) is best known for using electrolysis to isolate and discover many elements. He is credited with isolating or discovering sodium, calcium, boron, barium, magnesium, iodine, chlorine, and potassium. He also invented a safety lamp for miners called the Davy lamp. He also named nitrous oxide as laughing gas.

Carbon dioxide has one carbon atom and two oxygen atoms, and a molecular weight of 44 grams per mole. The oxygen in the air is actually O2, or molecular oxygen, with a molecular weight of 32. Hence, carbon dioxide has a higher density, or is heavier than oxygen.

Cadmium is most commonly used as control rods in the nuclear reactors. Cadmium absorbs neutrons in the reactors, preventing them from creating additional fission events.

Zinc is used in galvanisation process. Galvanization is the process of applying a protective zinc coating to steel or iron, to prevent rusting.

Molybdenum is commonly used in steel alloys to increase strength, hardness, electrical conductivity and resistance to corrosion and wear.

Hydrocarbons are those compounds which contains Hydrogen and carbon. Some of the important hydrocarbon fuels are LPG, CNG, Petrol, Coal gas etc.

Mercury cell consists of zinc – mercury amalgam as anode and a paste of HgO and carbon as the cathode. The electrolyte is a paste of KOH and ZnO. It is suitable for low current devices like hearing aids, watches, etc.

d-block elements are the elements of Group 3 to 12 in the centre of the Periodic Table. All of them are metals. These are characterised by the filling of inner d orbitals by electrons.

Rusting is the corrosion of Iron in which iron (Fe) combines with oxygen to form rust, or iron oxide. Fe₂O₃. nH₂O is usually called as hydrated ferric Oxide.

The principal quantum number also helps in identifying the shell. As the value of ‘n’ increases, the number of allowed orbital increases and are given by n².

According to de Broglie, every object in motion has a wave character. As per de Broglie’s relation, mass and wavelength are inversely proportional to each other.

Alumina is the common name given to aluminum oxide (Al²O³). It is produced from bauxite to get pure aluminium metal.

Mercury is a chemical element with the symbol Hg and atomic number 80. The element is also known as quicksilver for its mobility. Mercury is one of the oldest and deadliest poisons, a highly toxic metal mined from a brilliant red ore.

Calcium oxide (CaO), commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, caustic, alkaline crystalline solid at room temperature.