Explanation: Unsaturated hydrocarbons are organic compounds that are entirely made up of carbon and hydrogen atoms and consist of a double or a triple bond between two adjacent carbon atoms.

Explanation: Trisulfur. S3 is an allotrope of sulphur. Allotropy is the property of some chemical elements to exist in two or more different forms, in the same physical state, known as allotropes of the elements. Other Allotropes of Carbon : graphene and buckminsterfullerene.

Explanation: Diene is a covalent compound that contains two double bonds.

Explanation: Carbon and its compounds get easily oxidised when subjected to combustion. For example alcohol on oxidation is converted to carboxylic acid. Hydrocarbons {Saturated, Unsaturated , Cycloalkanes, Aromatic, Aliphatic, and Alicyclic. Oxidation (gain of oxygen), Reduction (loss of oxygen), Redox reaction (oxidation and reduction occurring together).

Explanation: Propane (C3H8) and butane (C4H10). Ethyl Mercaptan is added to the gas to make it smell like rotten eggs. Liquefied natural gas (LNG) and Compressed natural gas (CNG) mainly composed of methane (CH4). Biogas is a combination of two-thirds of methane (CH4) and the rest is mostly carbon dioxide (CO2).

Explanation: 2, 3 – Dimethylbutane is an isomer of hexane. Isobutane is an alkane that is propane substituted by a methyl group at position two. Butadiene is the raw material for many elastomers, ABS (acrylonitrile butadiene styrene polymer) and in low quantities for nylon and few others.

Explanation: Nitromethane is used to make industrial antimicrobials and pharmaceuticals, and is also used as a soil fumigant and as a fuel in race car engines.

Explanation: Sedimentation is the process in which particles separate from a liquid because of gravity.

Explanation: Alkanes are a series of compounds that contain carbon and hydrogen atoms with single covalent bonds.

Explanation: Chloroethane (CH3CH2Cl). Chloromethane (CH3Cl),1- Chloropropane (C3H7Cl), and 3- Chlorohexane (C6H13Cl).

Explanation: Ester is a chemical compound derived from an acid in which at least one –OH hydroxyl group is replaced by an –O– alkyl group, as in the substitution reaction of a carboxylic acid and an alcohol. Example- Ethyl acetate, propyl methanoate, etc. The term ester was introduced by German chemist Leopold Gmelin.

Explanation: Paradichlorobenzene (C6H4Cl2) is used as a fumigant insecticide to control cloth moths. Ethylbenzene (C6H5CH2CH3) is to manufacture styrene, a compound used to make plastics. Benzoyl chloride (C7H5ClO) is mainly useful for the production of peroxides. Chlorobenzene (C6H5Cl) is used primarily as a solvent, a degreasing agent, and a chemical intermediate.

Explanation: International Union of Pure and Applied Chemistry (IUPAC). Suffix – A functional group belonging to the molecule which follows the root of the name. Prefixes – They indicate the presence of side chains or substituent groups in the given organic molecule.

Explanation: Ethanol (CH3CH2OH) is used in the manufacture of drugs, plastics, lacquers, polishes, plasticizers, and cosmetics.

Explanation: Monosaccharides include glucose (dextrose), fructose, galactose, xylose and ribose. Oligosaccharides include sucrose, lactose and maltose. Starch, cellulose, and glycogen are some examples of polysaccharides.

Explanation: The melting point of graphite is slightly larger than the melting point of diamond because in graphite C-C bonds have a partial double-bond character and hence are stronger and more difficult to break.

Explanation: Atomic mass is defined as mass equal to one twelfth of the mass of a Carbon atom. The mass of any isotope of any element is expressed in relation to the Carbon-12 standard.

Explanation: Pyruvate is generated through glycolysis. Glycolysis begins with the six-carbon monosaccharide – glucose. In the first few steps, glucose undergoes phosphorylation and isomerization to produce fructose -6-phosphate. Another phosphorylation reaction facilitates the splitting of this hexose sugar into two 3-carbon molecules – glyceraldehyde phosphate (G3P) and dihydroxyacetone phosphate (DHAP).

Explanation: 3, 8. Propane is an alkane with the chemical formula C3H8 . As a type of hydrocarbon, it can undergo hydrocarbon combustion, which gives off heat.

Explanation: Benzene is an organic chemical compound with the molecular formula C6H6 . The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each, where all the bonds are identical. It has the shape of a regular hexagon, with bond angles of 120°.

Explanation: Magnesium and Lithium are almost of the same sizes and electronegativity values are nearly the same because both are found together in nature. A Diagonal Relationship is said to exist between certain pairs of diagonally adjacent elements in the second and third periods of the periodic table. These pairs (Li & Mg, Be & Al, B & Si, etc.) exhibit similar properties.

Explanation: Inert gases : These gases are called so because they are chemically inert i.e. they do not readily undergo chemical reactions easily. Presence – 18th group. Elements – Helium [He – 2], Neon [Ne – 10], Argon [Ar – 18], Krypton [Kr – 36], Xenon [Xe – 54], Radon [Rn – 86].

Explanation: Moseley rearranged the elements in the periodic table on the basis of atomic numbers. Examples: Oxygen ( 16O8) – Atomic number (Z) – 8 and atomic mass(A) – 16.

Explanation: Alkaline earth metals : Second most reactive family of elements, present in group 2 of the modern periodic table. Elements and their atomic number : Alkaline earth metals – Beryllium (4), Magnesium (12), Calcium (20), Strontium (38), Barium (56). Halogen (Group 17 or Group VIIA) – Fluorine (9), Chlorine (17), Bromine (35), Iodine (53). Oxygen family (Group 16 or Group VIA) – Oxygen (8), Sulphur (16), Selenium (34).

Explanation: Nitrogen (N). Other elements with their atomic number: Silicon (Si, 14), Phosphorus(P, 15), Sulphur(S,16), Argon (Ar, 18), Potassium (K, 19), Scandium(Sc, 21), Titanium (Ti, 22), Calcium (Ca, 20), Chlorine (Cl, 17), Oxygen (O, 8).

Explanation: Magnesium (Mg, 12). Lithium (Li,3), Sodium (Na, 11), Potassium (K, 19) belong to group 1A (Alkali Metals Group) of the periodic table and only Magnesium belongs to group 2A (Alkali Earth Metals Group) of the periodic table.

Explanation: Cu (copper), Fe (Iron), Ni (nickel), Ti (titanium). Transition elements : Those elements which have partially filled d-orbitals. The names transition metals and inner transition metals are often used to refer to the elements of d-and f-blocks respectively. Some Transition metals – Scandium (Sc), vanadium (V), chromium (Cr), manganese (Mn), cobalt (Co), zinc (Zn).

Explanation: William Ramsay – British physical chemist who discovered four gases (neon, argon, krypton, xenon) and showed that they (with helium and radon) formed an entire family of new elements, the noble gases. Award: Nobel Prize (1904). John Newlands: “Law of octaves “ When elements are arranged in increasing order of their atomic masses, every eighth element has the same properties as the first element. Glenn T Seaborg: His work on isolating and identifying transuranium elements (those heavier than uranium).

Explanation: There are six groups of p–block elements in the periodic table numbering from 13 to 18. Boron, carbon, nitrogen, oxygen, fluorine and helium head the groups. Their valence shell electronic configuration is ns2 np1-6 (except for He). The maximum oxidation state shown by a p-block element is equal to the total number of valence electrons. In the P block of periodic table the non-metallic character of elements decreases down the group. In fact the heaviest element in each p-block group is the most metallic in nature.

Explanation: The 15 elements that are part of the Actinides series are: Actinium (Ac), Thorium (Th), Protactinium (Pa), Uranium (U), Neptunium (Np), Plutonium (Pu), Americium (Am), Curium (Cm), Berkelium (Bk), Californium (Cf), Einsteinium (Es), Fermium (Fm), Mendelevium (Md), Nobelium (No), and Lawrencium (Lr).

Explanation: Group 13 Elements: The Boron Family – Boron is a typical non-metal. Aluminium is a metal but shows many chemical similarities to boron, and gallium, indium and thallium are almost exclusively metallic in character. Boron is a fairly rare element, mainly occurs as orthoboric acid (H3BO3), borax (Na2B4O7 ·10H2O) and kernite (Na2B4O7 ·4H2O). There are two isotopic forms of boron 10B (19%) and 11B (81%).

Explanation: Radon (Rn, 86). It is a radioactive element. It is used in some hospitals to treat tumours by sealing the gas in minute tubes. Group 18 (Noble gas): The full valence electron shells of these atoms make noble gases extremely stable and unlikely to form chemical bonds because they have little tendency to gain or lose electrons. The other radioactive elements are helium (He, 2), neon (Ne,10), argon (Ar, 18), krypton (Kr, 36), xenon (Xe, 54), radon (Rn, 86), and oganesson (Og, 118).

Explanation: The half-life (t1/2) is the time in which the concentration of a reaction or radioactive substances is reduced to one-half of its initial concentration. t1/2 = 0.693/λ. Here λ is the disintegration constant. Other elements and their atomic number: Darmstadtium (Ds) -110, Nihonium (Nh) – 113, Nobelium (No) – 102, Einsteinium (Es) – 99, Fermium (Fm) – 100, Plutonium (Pm) – 61.

Explanation: Alkali metals: Lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr) are soft, shiny, low-melting, highly reactive metals which tarnish quickly when exposed to air due to reaction with Oxygen, moisture oxides, hydroxides, and CO2 present in air to form carbonates.

Explanation: Law of Octaves – Every eighth element has similar properties when the elements are arranged in the increasing order of their atomic masses.

Explanation: Beryllium (Be, 4). Mixing it with metals increases their electrical and thermal conductivity.

Explanation: It is a silvery radioactive metallic element that glows in the dark due to its intense radioactivity with a blue light. It was discovered in 1899 by André-Louis Debierne. Groups 3 to 12 elements are called d-block or transition elements.

Explanation: 63.

Explanation: Praseodymium (Pr) – It can be found in houses in equipment such as colour televisions, fluorescent lamps, energy-saving lamps and glasses. It is solid at room temperature.

Explanation: Neon is an inert gas and element of the 18th group of the modern periodic table. Electronic configuration of some elements : Neon (Ne, Atomic number – 10) – [He], 2s2 2p6 (the last orbit is completely filled). Lithium (Li, Atomic number – 3) – [He], 2s1 (last orbit is not completely filled). Sodium (Na, Atomic number – 11) – 1s2 , 2s2 2p6 , 3s1 (or) [Ne] 3s1 .

Explanation: Li and Mg.

Explanation: Francium (Fr): It is in liquid form at room temperature. Second-most electropositive element (after cesium).

Explanation: Symbol – Bh. The namesake of Bohrium, Niels Bohr, was awarded the Nobel Prize in 1922 for his work on the structure of atoms.

Explanation: Nihonium (Nh) – It is an extremely radioactive synthetic chemical element with a stable isotope, atomic mass – 286 u, has a half-life of 10 seconds and is a transactinide element in the p-block.

Explanation: Newland’s relation.

Explanation: 9, Fluorine (F). Group 17 (Halogen elements):- Chlorine (Cl, 17), Bromine (Br, 35), Iodine (I, 53), Astatine (At, 85), and Tennessine (Ts, 117).

Explanation: Hydrogen (H). Alkali metals – They form hydroxides on reaction with water which are strongly alkaline in nature. Physical Properties of Alkali metals – Silvery white, soft, light, malleability, high thermal and electrical conductivity.

Explanation: Period – A horizontal row of the periodic table. Total Period – 7 periods, with each one beginning at the far left. Group – A column of elements in the periodic table of the chemical elements. Total Groups – 18.

Explanation: Newlands’ law of octaves – when elements are arranged in increasing order of their atomic masses, the properties of the eighth element are a repetition of the properties of the first element. It was found that the Law of Octaves was applicable only upto calcium, as after calcium every eighth element did not possess properties similar to that of the first.

Explanation: They are – Oxygen (O), Sulphur (S), Selenium (Se), Tellurium (Te) and Polonium (Po), and Livermorium (Lv).