Absolute temperature is the temperature on Kelvin scale on which zero is marked OS -273’C.

Absolute zero is the lowest possible temperature and is. equal to -273’C.

Allotropes: ore different physical forms of a pure element.

Alloy is a solid solution of metals; ii may contain small number of non-metals.

Alpha particle is doubly positively charged helium nuclei. amu is the abbreviation for atomic moss unit. II is exactly 1 /12th moss of one atom of corbon-12.

Anion is on atom or group of atoms having a negative charge.

Anode is on electrode al which oxidation occurs.

Atmosphere is the unit of pressure of air at the earth’s surface.

Atom is the smallest particle of an element to retain the properties of the element.

Atomic mass is the exact moss of one atom of an element.

Atomic number is the number of protons in the nucleus of on atom.

Boiling point is the temperature at which vapour pressure of a liquid equals the atmospheric or external pressure over the liquid.

Bonding is the term used to describe ways in which atoms ore held together in elements and compound.

Cathode is the electrode at which reduction occurs.

Cation is on atom or group of atoms having a positive charge.

Charles’s Law describes relationship between volume occupied by a gas and temperature at constant pressure.

Chemical bond is the force that holds two or more atoms together in a substance.

Chemistry is the study of matter, its composition, properties and the interaction of atoms as they react to form new substances.

Colloid is a heterogeneous mixture of a substance dispersed through a medium.

Compound is a substance mode up of elements in fixed ratio.

Concentration is the measure of the amount of solute dissolved in a solution.

Condensation is the change of a gas into a liquid.

Conductor is a substance that con conduct electric current.

Covalent bond is a bond formed by the mutual shoring of electrons between two atoms.

Distillation is the process for purifying a liquid by evaporating it, condensing the   vapours and collecting the liquid in a clean container.

Double bond is a covalent bond formed by two pairs of shored electrons.

Electrolyte is a substance which in fused form or in solution form allows current to flow through it.

Electron is the sub-atomic negatively charged particle in on atom.

Electron configuration is the arrangement of electrons in orbitals.

Electron shells ore sets of energy levels corresponding to a single value of n.

Electronegativity is the power of on atom to attract electrons to itself.

Element is the pure substance in which all the atoms hove some atomic number.

Energy levels are the discrete energies of electron in atom.

Evaporation is the escape of molecules of a liquid through the surface.

Formula mass is the sum of atomic mosses of all the atoms present in the compound. It can also be defined as the moss of one formula unit or molecule in amu or moss of one mole of the compound in grams.

Formula unit is the simplest formula of on ionic compound.

Freezing point is the temperature at which a liquid change to a solid.

Gas is one of the physical states of matter that has neither any definite shape nor fixed volume.

Gold is on elemental metal; its symbol is Au.

Gram formula mass is the moss of l mole of a compound or element in grams.

Group refers to the vertical column on the periodic table.

Halogens are the elements present in VIIA group on the periodic table.

Hydrochloric acid is on aqueous solution of hydrogen chloride.

Hydrogen bond is on intermolecular force due to the interaction of lone pair present on N, O or F atom and the partially positively charged hydrogen of another molecule attached with N, O or F.

Inorganic refers to a compound mode up primarily of atoms other than carbon.

Intermolecular forces are the attractive forces between the molecules.

Ion is on atom or a molecule possessing on electric charge.

Ionic bond is the bond formed by the attraction of oppositely charged ions.

Isotopes ore atoms of on element that differ in the number of neutrons.

Kelvin is a temperature scale, the zero of which corresponds to -273’C.

Liquid is one of the states of matter that has definite volume but no definite shape.

Lone pair is a pair of non-bonding valence electron or a pair of electrons that ore not shored in covalent bonding.

Main group elements ore elements belonging to sub-group A on the periodic table.

Mass number is the sum of the number of protons and neutrons in on atom.

Matter is anything that occupies space and has moss.

Melting point is the temperature at which a substance melt.

Metals ore elements that ore good conductor of electricity and heat and tends to form positive ions.

Molar mass is the moss of one mole of a compound or element in grams.

Molarity is the number of moles of solute per dm3 of solution.

Mole is Avogodro’s number of atoms, molecules or formula units. It can also be defined as the atomic moss, formula moss or molecular moss of a substance expressed in grams.

Molecular mass is the sum of atomic mosses of all the atoms present in a molecule.

Molecule is a group of atoms held by a chemical bond and behaves as on independent unit.

Neutron is a sub-atomic neutral particle in the nucleus of on atom.

Non-metal is on element that is a bad conductor of electricity and tends to form negative ion.

Nucleus is the positively charged center of on atom.

Octet is eight electron configurations in the valence shell.

Orbitals ore regions of space around the nucleus where electron is likely to be present.

Organic chemistry is the study of carbon compound or the study of hydrocarbons and their derivatives.

Organic compounds ore compounds mainly composed of carbon atoms.

Oxidation is the loss of electron by on element.

Oxidation slate is the actual charge on an ion or apparent charge on an atom in a molecule.

Oxidizing agent is the reactant containing the element that is reduced.

Period refers to the horizontal row in the periodic table.

Periodic table is a systematic arrangement of elements based on electron configuration and periodic behavior.

Polar covalent bond is a bond in which electrons ore shored unequally between two atoms. Thus, one atom bears partial positive charge and the other a partial negative charge.

Proton is the positively charged sub-atomic particle in the nucleus of on atom.

Reactant is a substance consumed in a chemical reaction.

Redox reaction is on oxidation and reduction reaction.

Reduction is the gain of electron by on atom.

Reducing agent is the reactant containing the element that is oxidized. Solid is one of the three states of matter, it has a definite shape and definite volume.

Solubility is the amount of solute that dissolved in 100g of water at a particular temperature.

Solute is the component of solution that is present in relatively small amount. Solvent is the component of solution that is present in relatively larger amount. S-orbital is a spherical shape orbital.

Sublimation is the conversion of a solid directly into a gas.

Technology is the application of scientific knowledge to serve some practical purpose.

Torr is the unit of pressure equal to 1mm of Hg.

Triple bond is a covalent bond involving the shoring of three pairs of electrons. Valence electrons ore the electron in the outer most energy level of the atom. Valence shell is the outermost energy level of the atom.

Vapour pressure is the pressure exerted by the vapours of a liquid in equilibrium with its liquid at a particular, temperature.

Zero group refers to VIIIA group on the periodic table.


Alkaline earth the elements of group 2 ore called alkaline earth metals.
Alkali metals: the elements of group 1 ore called alkali metals.
Allotrope: the elements which show allotropy ore called allotropes or allotropic forms.
Allotropy: Existence of an element in more than one crystalline form
Amorphous solids:     those solids in which the atoms, ions or molecules ore arranged in a random manner.
Anode: ‘hot electrode which is positively charged being electron deficient. Oxidation tokes place at this electrode
Atom: The smallest particle of an element which may or may not exist independently.
Atomic mass A: the moss of the atom expressed in atomic moss units.
 Atomic model: II is a set of assumptions which can be used to explain the interrelated experimental  observations  and  properties  of on atom in terms of familiar systems. The correctness of themodel is inferred from experimental facts.
Atomic number, Z:      the number of protons in the nucleus of on atom of the element. II is also equal to the number of electrons   surrounding the nucleus in a neutral atom.
Atomic radius: II is the overage distance between the nucleus of the atom and its outermost shell. 1 t is to be assumed that theatom is spherical. Since, the outer boundaries ore notsharp for on atom, so atomic radius is not on exact
Atomic size: the atomic size is the distance from the centre of the nucleus to the outermost shell of electrons in the atom of
Atomic mass unit: It is the moss of 1 / 12th of on atom of lighter isotope ofcarbon.
Average atomic mass: It is the overage of atomic mosses of all the isotopes of an element
Avogadro’s number: It is the number of atoms, molecules, formula units or ions present in one mole of the element, a compound, or an   onic substance. Its value is 6.02 x 1023.
Bohr’s atomic model: Simplest atomic model of atom based upon the quantum  theory of radiation and lows of the classical mechanics.
Boiling point: ‘he temperature at which the vapour pressure of liquid becomes equal to the external pressure. If the external pressure is one atmosphere, the boiling point is called
Bond energy: It is the overage amount of energy which is required to break all the bonds of a particular type in a one mole ofhe substance. It is measured in kJ mol ·1•
Bond pair: It is a pair of electrons which is shored between twobonded atoms. This shored pair may be due to mutual shoring or donated by one atom only.
Boyle’s law: he volume of given amount of a gas is inverselyproportional to the pressure of the gas at a constant
Branches of chemistry: Some important branches of chemistry ore.(i) Physical chemistry (ii) Inorganic chemistry(iii) Organic chemistry (iv) Analytical chemistry(v) Bio-chemistry (vi) Applied chemistry or Industrial
Cathode: hat electrode which is negatively charged being rich in electron Reduction tokes place at this electrode.
Charles’s law: The volume of the given amount of a gas is directlyproportional to the absolute temperature of the gas, at
Chemical bond: It is attractive force which binds two or more atoms, ions,or molecules. It may be due to shoring of electron or transference of electrons
Chemical reactivity: Chemical reactivity is measured by the relative tendencyof on element to lose or gain electrons in chemical
Coordinate covalent bond: That type of a bond which is formed by the shoring of on electron pair, donated by one atom only. It is also calleddonor-acceptor bond.
Covalency: he number of electrons, which on atom contributestowards mutual shoring during the formation of a
Covalent bond: hot type of a bond which is produced by the mutual shoring of electrons between the two atoms
Covalent radius: Covalent radius is half the distance between the nuclei ofthe two similar atoms covalently bonded to each other by a single bond
Crystal lattice: he arrangement of the lattice point in a crystal in adefinite pattern in three-dimensional space, it is also called space lattice.
Crystalline solids: hose solid substances in which the atoms, ions ormolecules ore arranged in regular, repeating, three- dimensional well-ordered pattern.
Diffusion: The spontaneous mixing of the molecules of different gases by random motion and collision to form
Dipole: II is that molecule which has two poles in ii. These poles ore created due to difference of electronegolivilies.
Dipole-dipole forces:Dipoles: Those forces of attractions which ore present between positive end of one polar molecule and the negative end of the other polar molecule,A polar molecule like HCI (H-CI) which has positive andnegative charge centres al the ends of the covalent
Double covalent A bond formed by the mutual shoring of two electron
Ductility: The properly of the metals to be converted into wires.
Effusion: The passage of gas molecules one by one without collisionthrough a pinhole.
Electrochemical cell: II is a cell in which the electrodes ore dipped into on electrolyte and redox reaction tokes place by the passage of on electrical current. II is also defined as onarrangement in which electrical current is produced by a
Electrochemistry: II is the branch of chemistry which deals with the changeof electrical energy into chemical energy or the change of chemical energy into electrical energy.
Electrode:Electrolysis: An electro conducting substance through which theII is the process in which the electrical current is used tocarry out on oxidation-reduction reaction.
Electrolyte: hot substance which allows the electrical current to pass through in the solution or molten stole.
Electrolytic cell: A cell which uses the electrical current to carry out a redox reaction.
Electrolytic conduction: Electron affinity: This is the conduction in which electrical current is carried  by positively and negatively charged ions formed in thesolution due to ionization of electrolvte.It is the minimum amount of energy released or absorbed, when on electron is added to the outermost shell of thegaseous atom. It is measured in kJ mole ·1•
Electron: A negatively Charged particle which is 1836 times lighter than proton having moss 9.1 x 10-31 kg and charge equal
Electronegativecharacter: he tendency of on element to accept electrons to form on onion
Electronegativity: It is the relative tendency of on atom to attract the shored po• of electrons towards itself in a bond.
Formula mass: Formula moss of a substance is equal to the sum of the atomic mosses of all the atoms present in the empirical
Free Radicals: A free radical is a molecule, on atom or on ion containing on odd number of electrons.
Galvanic or voltaic cell: That cell which produces electrical current as a result of a redox reaction.
Gas laws: Gos lows are the relationships between the volume of the given amount of the gas and prevailing conditions oftemperature and pressure.
Gram atom: The atomic moss of an element expressed in grams.
Gram formula: The formula moss of on ionic substance expressed in
Gram ion: he molar moss of on ionic substance expressed in
Gram molar mass: the molar moss of a substance expressed in grams.
Heat of solution: II is the amount of heat absorbed or evolved when one mole of solute is dissolved in large excess of solvent at agiven temperature.
Heterogeneousmatter: Matter that is made up of two or more componentswhich ore physically distinct.
Heteronucleardiatomic molecule: A molecule having two different atoms of two elements.
Homogeneousmatter: Matter which has uniform composition and identicalproperties throughout the phase.
Homonucleardiatomic molecule: A molecule which consists of two identical atoms.
Hydrogen bond: he bond between the hydrogen atom of one molecule and a more electronegative atom of the some or
Ion: A positively or negatively charged atom or group of
Ionic bond: ·hot type of a bond which is produced due to the nettransference of electron from one atom to the other.
those crystalline solids in which positively and negatively charged ions ore held together through electrostaticforce of attraction.
Ionic solids:
Ionization energy: II is the amount of energy, required to remove theelectron from outermost shell of on isolated in its gaseous
Ionization: II is a process of splitting up of on ionic compound due to the presence of charged particles, when fused or
Isotherm: A graph between pressure and volume of the gas atconstant temperature and the number of moles. It is a
Liquefaction: he process of conversion of a gaseous substance into the liquid stale
Macromolecule: Molecules of high molar masses usually more than 10,000.
Malleability: Matter: the property of the metals to be converted into thin Anything which has mass and occupies space.
Mendeleev’s Periodic“able: the tabular arrangement of elements in ascending orderof their atomic masses.
Metallic bond: he force of attraction that bonds positive metal ion tothe number of electrons within its sphere of influence.
Metallic conduction: It is the conduction of electricity due to the freemovement of the electrons throughout the metallic
Metallic solids: those crystalline solids in which the metal atoms are heldtogether by metallic bonds.
Mixture: A material obtained by mixing two or more elements or compounds in any ratio such that the properties of the elements or the compounds forming the mixture do notchange al all.
Modern periodic law: The physical and chemical properties of elements are the periodic function of their atomic numbers.
Molar mass: It is the mass of 1 mol of a substance.
Molarity (M): It is the number of moles of solute dissolved per dm ofsolution.
Mole: The atomic mass of an element, molar mass of acompound, formula mass of an ionic substance and ionic mass of ionic substance expressed in grams.
Molecular formula: That formula of a substance which gives us the Kind andtotal number of atoms present in the molecule of a
Molecular ion: Any charged molecular species.
Molecular mass: Molecule: It is the mass obtained by adding the masses of all the atoms in the molecular formula of a substance.The smallest particle of a substance which can existindependently.
Negative ion or anion: A species which has negative charge.
Neutron: It is the particle present in nucleus of the atom having mass very close to that of proton and is equal to 1.675
Octet rule: The tendency of the atoms to attain a maximum of     eight electrons in the valence shell.
Orbit: The fixed path around the nucleus of the atom, where the electrons move.
Oxidation number: It is an apparent charge positive, negative or zero on anatom of an element in a molecule or an ion.
Oxidation: Loss of electrons is called oxidation. Increase of oxidation number is also called oxidation.
Oxidizing agents: A substance which oxidizes the other and is itselfreduced in a chemical reaction.
Partially miscible liquids: Those liquids which are dissolved into one another to a limited extent.
Periodicity ofproperties: The repetition of properties after regular intervals in theperiodic table.
Polar covalent bond: The bond between two unlike atoms which differ in their affinities for electrons.
Polyatomic molecule: A molecule having more than two atoms.
Positive ion or cation: A species which has positive charge.
Proton: It is a positively charged particle with mass 1.6726 x 10**kg and having a charge of 1.602 x 10 19 C.
Reactivity of metals: The reactivity of metals is measured in term of theirtendency to lose electrons from their outermost shell.
Reactivity of non-metal: The reactivity of a non-metal is measured in terms oftheir tendency to gain electrons to form an anion.
Redox reaction: Oxidation reduction reaction is also called redox
Reducing agent: That substance which reduces the other and is oxidizedItself.