Periodic Table Trends- Atomic size, Melting & Boiling Point Trend

The modern periodic table is based on the law that the properties of an element are a periodic function of their atomic number. These properties are related to the electronic configuration of the elements.

We observe a common trend in properties as we move across a period from left to right or down the group. This trend in properties is known as periodic properties.

The important periodic properties are atomic size, metallic character, non-metallic character, ionization potential, electron affinity, and electronegativity.

The modern periodic table is based on the law that the properties of an element are a periodic function of their atomic number. These properties are related to the electronic configuration of the elements.

Periodic Table Trends:

The following trend in periodic properties of elements is observed:

The distance between the centre of the nucleus and the outermost shell of an atom is known as the atomic radius. In a group the atomic size increases due to the addition of shells as we move from one period to another. Across a period the atomic size decreases as the number of shells remain the same while the nuclear charge increases. This leads to the pulling of electrons from the outermost shell towards the nucleus thereby decreasing the size.

The elements which lose electrons to form cations are known as metals. Metallic character increases as we move down the group because the atomic size increases which lead to easy loss of electrons. On the other hand, it decreases across a period as we move from left to right. This happens because there is an increase in nuclear charge which makes it difficult for an atom to lose electrons.

The elements which have a tendency to gain electrons are known as non-metals. The tendency to gain electrons increases on moving across a period due to an increase in the nuclear charge and a decrease in the atomic size.  Hence, non-metallic character increases across a period. As we move down the group the non-metallic character decreases due to an increase in the atomic size.

Ionization potential is defined as the amount of energy required to remove an electron from the outermost shell of a gaseous atom and convert it into a positively charged gaseous ion. The periodic properties in terms of ionization potential increase because the atomic size decreases across a period due to an increase in the nuclear charge. When we move down the group, ionization potential decreases due to the increase in atomic size.

The melting point of an element is basically the energy required to change the state of an element from its solid state to its liquid state. Which essentially implies breaking a few bonds. Thus, higher the stronger the bond between the atoms, the higher will be the melting point. Let us look at the elements in the ascending order of their melting points.

Melting PointElementAtomic Number
-272Helium  (He)2
-259Hydrogen (H)1
-249Neon (Ne)10
-220Fluorine  (F)9
-218Oxygen  (O)8
-210Nitrogen N7
-189Argon Ar18
-157Krypton Kr36
-112Xenon Xe54
-101Chlorine Cl17
-71Radon Rn86
-39Mercury Hg80
-7Bromine Br35
27Francium Fr87
29Cesium Cs55
30Gallium Ga31
39Rubidium Rb37
44Phosphorus P15
64Potassium K19
98Sodium Na11
113Sulphur S16
114Iodine I53
157Indium In49
180Lithium Li3
217Selenium Se34
232Tin Sn50
254Polonium Po84
271Bismuth Bi83
302Astatine At85
303Thallium Tl81
321Cadmium Cd48
327Lead Pb82
420Zinc Zn30
449Tellurium Te52
630Antimony Sb51
639Magnesium Mg12
640Neptunium Np93
640Plutonium Pu94
660Aluminium Al13
700Radium Ra88
725Barium Ba56
769Strontium Sr38
795Cerium Ce58
816.8Arsenic As33
822Europium Eu63
824Ytterbium Yb70
827Nobelium No102
839Calcium Ca20
860Einsteinium Es99
900Californium Cf98
920Lanthanum La57
935Praseodymium Pr59
937Germanium Ge32
962Silver Ag47
986Berkelium Bk97
994Americium Am95
1010Neodymium Nd60
1050Actinium Ac89
1064Gold Au79
1072Samarium Sm62
1083Copper Cu29
1100Promethium Pm61
1132Uranium U92
1245Manganese Mn25
1278Beryllium Be4
1311Gadolinium Gd64
1340Curium Cm96
1360Terbium Tb65
1410Silicon Si14
1412Dysprosium Dy66
1453Nickel Ni28
1470Holmium Ho67
1495Cobalt Co27
1522Erbium Er68
1523Yttrium Y39
1527Fermium Fm100
1535Iron Fe26
1539Scandium Sc21
1545Thulium Tm69
1552Palladium Pd46
1568Protactinium Pa91
1627Lawrencium Lr103
1656Lutetium Lu71
1660Titanium Ti22
1750Thorium Th90
1772Platinum Pt78
1852Zirconium Zr40
1857Chromium Cr24
1890Vanadium V23
1966Rhodium Rh45
2150Hafnium Hf72
2200Technetium Tc43
2250Ruthenium Ru44
2300Boron B5
2410Iridium Ir77
2468Niobium Nb41
2617Molybdenum Mo42
2996Tantalum Ta73
3045Osmium Os76
3180Rhenium Re75
3410Tungsten W74
3500Carbon C6
Mendelevium Md101
Rutherfordium Rf104
Dubnium Db105
Seaborgium  Sg106
Bohrium Bh107
Hassium Hs108
Meitnerium Mt109
Darmstadtium Ds110
Roentgenium Rg111
Copernicium Cn112
Nihonium Nh113
Flerovium Fl114
Moscovium Mc115
Livermorium Lv116
Tennessine Ts117
Oganesson Og118

Just like how the strength of the bonds between atoms affect the Melting Point, the boiling point depends on the heat energy required to create a transition from liquid to gaseous state. Have a look at this table with the elements of the periodic table arranged in order of increasing boiling points.

Boiling 
point
ElementSymbolAtomic number
-269HeliumHe2
-253HydrogenH1
-246NeonNe10
-196NitrogenN7
-188FluorineF9
-186ArgonAr18
-183OxygenO8
-153KryptonKr36
-108XenonXe54
-62RadonRn86
-35ChlorineCl17
58.8BromineBr35
184IodineI53
280PhosphorusP15
337AstatineAt85
357MercuryHg80
445SulphurS16
613ArsenicAs33
677FranciumFr87
678CesiumCs55
685SeleniumSe34
688RubidiumRb37
760PotassiumK19
765CadmiumCd48
774PotassiumK19
883SodiumNa11
907ZincZn30
962PoloniumPo84
990TelluriumTe52
1090MagnesiumMg12
1140BariumBa56
1347LithiumLi3
1384StrontiumSr38
1457ThalliumTl81
1466YtterbiumYb70
1484CalciumCa20
1560BismuthBi83
1597EuropiumEu63
1727ThuliumTm69
1737RadiumRa88
1740LeadPb82
1750AntimonySb51
1900SamariumSm62
1962ManganeseMn25
2000IndiumIn49
2212SilverAg47
2270TinSn50
2355SiliconSi14
2403GalliumGa31
2467AluminiumAl13
2510ErbiumEr68
2550BoronB5
2562DysprosiumDy66
2567CopperCu29
2607AmericiumAm95
2672ChromiumCr24
2720HolmiumHo67
2732NickelNi28
2750IronFe26
2807GoldAu79
2830GermaniumGe32
2832ScandiumSc21
2870CobaltCo27
2927PalladiumPd46
2970BerylliumBe4
3000PromethiumPm61
3041TerbiumTb65
3127PraseodymiumPr59
3127NeodymiumNd60
3200ActiniumAc89
3233GadoliniumGd64
3235PlutoniumPu94
3257CeriumCe58
3287TitaniumTi22
3315LutetiumLu71
3337YttriumY39
3380VanadiumV23
3469LanthanumLa57
3727RhodiumRh45
3818UraniumU92
3827PlatinumPt78
3900RutheniumRu44
3902NeptuniumNp93
4377ZirconiumZr40
4527IridiumIr77
4612MolybdenumMo42
4790ThoriumTh90
4827CarbonC6
4877TechnetiumTc43
4927NiobiumNb41
5027OsmiumOs76
5400HafniumHf72
5425TantalumTa73
5627RheniumRe75
5660TungstenW74
 ProtactiniumPa91
 CuriumCm96
 BerkeliumBk97
 CaliforniumCf98
 EinsteiniumEs99
 FermiumFm100
 MendeleviumMd101
 NobeliumNo102
 LawrenciumLr103
 RutherfordiumRf104
 DubniumDb105
 SeaborgiumSg106
 BohriumBh107
 HassiumHs108
 MeitneriumMt109
 DarmstadtiumDs110
 RoentgeniumRg111
 CoperniciumCn112
 NihoniumNh113
 FleroviumFl114
 MoscoviumMs115
 LivermoriumLv116
 TennessineTs117
 OganessonOg118

Er. Neeraj K.Anand is a freelance mentor and writer who specializes in Engineering & Science subjects. Neeraj Anand received a B.Tech degree in Electronics and Communication Engineering from N.I.T Warangal & M.Tech Post Graduation from IETE, New Delhi. He has over 30 years of teaching experience and serves as the Head of Department of ANAND CLASSES. He concentrated all his energy and experiences in academics and subsequently grew up as one of the best mentors in the country for students aspiring for success in competitive examinations. In parallel, he started a Technical Publication "ANAND TECHNICAL PUBLISHERS" in 2002 and Educational Newspaper "NATIONAL EDUCATION NEWS" in 2014 at Jalandhar. Now he is a Director of leading publication "ANAND TECHNICAL PUBLISHERS", "ANAND CLASSES" and "NATIONAL EDUCATION NEWS". He has published more than hundred books in the field of Physics, Mathematics, Computers and Information Technology. Besides this he has written many books to help students prepare for IIT-JEE and AIPMT entrance exams. He is an executive member of the IEEE (Institute of Electrical & Electronics Engineers. USA) and honorary member of many Indian scientific societies such as Institution of Electronics & Telecommunication Engineers, Aeronautical Society of India, Bioinformatics Institute of India, Institution of Engineers. He has got award from American Biographical Institute Board of International Research in the year 2005.

CBSE Class 11 Chemistry Syllabus

CBSE Class 11 Chemistry Syllabus is a vast which needs a clear understanding of the concepts and topics. Knowing CBSE Class 11 Chemistry syllabus helps students to understand the course structure of Chemistry.

Unit-wise CBSE Class 11 Syllabus for Chemistry

Below is a list of detailed information on each unit for Class 11 Students.

UNIT I – Some Basic Concepts of Chemistry

General Introduction: Importance and scope of Chemistry.

Nature of matter, laws of chemical combination, Dalton’s atomic theory: concept of elements,
atoms and molecules.

Atomic and molecular masses, mole concept and molar mass, percentage composition, empirical and molecular formula, chemical reactions, stoichiometry and calculations based on stoichiometry.

UNIT II – Structure of Atom

Discovery of Electron, Proton and Neutron, atomic number, isotopes and isobars. Thomson’s model and its limitations. Rutherford’s model and its limitations, Bohr’s model and its limitations, concept of shells and subshells, dual nature of matter and light, de Broglie’s relationship, Heisenberg uncertainty principle, concept of orbitals, quantum numbers, shapes of s, p and d orbitals, rules for filling electrons in orbitals – Aufbau principle, Pauli’s exclusion principle and Hund’s rule, electronic configuration of atoms, stability of half-filled and completely filled orbitals.

UNIT III – Classification of Elements and Periodicity in Properties

Significance of classification, brief history of the development of periodic table, modern periodic law and the present form of periodic table, periodic trends in properties of elements -atomic radii, ionic radii, inert gas radii, Ionization enthalpy, electron gain enthalpy, electronegativity, valency. Nomenclature of elements with atomic number greater than 100.

UNIT IV – Chemical Bonding and Molecular Structure

Valence electrons, ionic bond, covalent bond, bond parameters, Lewis structure, polar character of covalent bond, covalent character of ionic bond, valence bond theory, resonance, geometry of covalent molecules, VSEPR theory, concept of hybridization, involving s, p and d orbitals and shapes of some simple molecules, molecular orbital theory of homonuclear diatomic molecules(qualitative idea only), Hydrogen bond.

UNIT V – Chemical Thermodynamics

Concepts of System and types of systems, surroundings, work, heat, energy, extensive and intensive properties, state functions. First law of thermodynamics – internal energy and enthalpy, measurement of U and H, Hess’s law of constant heat summation, enthalpy of bond dissociation, combustion, formation, atomization, sublimation, phase transition, ionization, solution and dilution. Second law of Thermodynamics (brief introduction)
Introduction of entropy as a state function, Gibb’s energy change for spontaneous and nonspontaneous processes.
Third law of thermodynamics (brief introduction).

UNIT VI – Equilibrium

Equilibrium in physical and chemical processes, dynamic nature of equilibrium, law of mass action, equilibrium constant, factors affecting equilibrium – Le Chatelier’s principle, ionic equilibrium- ionization of acids and bases, strong and weak electrolytes, degree of ionization,
ionization of poly basic acids, acid strength, concept of pH, hydrolysis of salts (elementary idea), buffer solution, Henderson Equation, solubility product, common ion effect (with illustrative examples).

UNIT VII – Redox Reactions

Concept of oxidation and reduction, redox reactions, oxidation number, balancing redox reactions, in terms of loss and gain of electrons and change in oxidation number, applications of redox reactions.

UNIT VIII – Organic Chemistry: Some basic Principles and Techniques

General introduction, classification and IUPAC nomenclature of organic compounds. Electronic displacements in a covalent bond: inductive effect, electromeric effect, resonance and hyper conjugation. Homolytic and heterolytic fission of a covalent bond: free radicals, carbocations, carbanions, electrophiles and nucleophiles, types of organic reactions.

UNIT IX – Hydrocarbons

Classification of Hydrocarbons
Aliphatic Hydrocarbons:
Alkanes – Nomenclature, isomerism, conformation (ethane only), physical properties, chemical reactions.
Alkenes – Nomenclature, structure of double bond (ethene), geometrical isomerism, physical properties, methods of preparation, chemical reactions: addition of hydrogen, halogen, water, hydrogen halides (Markovnikov’s addition and peroxide effect), ozonolysis, oxidation, mechanism of electrophilic addition.
Alkynes – Nomenclature, structure of triple bond (ethyne), physical properties, methods of preparation, chemical reactions: acidic character of alkynes, addition reaction of – hydrogen, halogens, hydrogen halides and water.

Aromatic Hydrocarbons:

Introduction, IUPAC nomenclature, benzene: resonance, aromaticity, chemical properties: mechanism of electrophilic substitution. Nitration, sulphonation, halogenation, Friedel Craft’s alkylation and acylation, directive influence of functional group in monosubstituted benzene. Carcinogenicity and toxicity.

To know the CBSE Syllabus for all the classes from 1 to 12, visit the Syllabus page of CBSE. Meanwhile, to get the Practical Syllabus of Class 11 Chemistry, read on to find out more about the syllabus and related information in this page.

CBSE Class 11 Chemistry Practical Syllabus with Marking Scheme

In Chemistry subject, practical also plays a vital role in improving their academic scores in the subject. The overall weightage of Chemistry practical mentioned in the CBSE Class 11 Chemistry syllabus is 30 marks. So, students must try their best to score well in practicals along with theory. It will help in increasing their overall academic score.

CBSE Class 11 Chemistry Practical Syllabus

The experiments will be conducted under the supervision of subject teacher. CBSE Chemistry Practicals is for 30 marks. This contribute to the overall practical marks for the subject.

The table below consists of evaluation scheme of practical exams.

Evaluation SchemeMarks
Volumetric Analysis08
Salt Analysis08
Content Based Experiment06
Project Work04
Class record and viva04
Total30

CBSE Syllabus for Class 11 Chemistry Practical

Micro-chemical methods are available for several of the practical experiments. Wherever possible such techniques should be used.

A. Basic Laboratory Techniques
1. Cutting glass tube and glass rod
2. Bending a glass tube
3. Drawing out a glass jet
4. Boring a cork

B. Characterization and Purification of Chemical Substances
1. Determination of melting point of an organic compound.
2. Determination of boiling point of an organic compound.
3. Crystallization of impure sample of any one of the following: Alum, Copper Sulphate, Benzoic Acid.

C. Experiments based on pH

1. Any one of the following experiments:

  • Determination of pH of some solutions obtained from fruit juices, solution of known and varied concentrations of acids, bases and salts using pH paper or universal indicator.
  • Comparing the pH of solutions of strong and weak acids of same concentration.
  • Study the pH change in the titration of a strong base using universal indicator.

2. Study the pH change by common-ion in case of weak acids and weak bases.

D. Chemical Equilibrium
One of the following experiments:

1. Study the shift in equilibrium between ferric ions and thiocyanate ions by increasing/decreasing the concentration of either of the ions.
2. Study the shift in equilibrium between [Co(H2O)6] 2+ and chloride ions by changing the concentration of either of the ions.

E. Quantitative Estimation
i. Using a mechanical balance/electronic balance.
ii. Preparation of standard solution of Oxalic acid.
iii. Determination of strength of a given solution of Sodium hydroxide by titrating it against standard solution of Oxalic acid.
iv. Preparation of standard solution of Sodium carbonate.
v. Determination of strength of a given solution of hydrochloric acid by titrating it against standard Sodium Carbonatesolution.

F. Qualitative Analysis
1) Determination of one anion and one cation in a given salt
Cations‐ Pb2+, Cu2+, As3+, Al3+, Fe3+, Mn2+, Ni2+, Zn2+, Co2+, Ca2+, Sr2+, Ba2+, Mg2+, NH4 +
Anions – (CO3)2‐ , S2‐, NO2 , SO32‐, SO2‐ , NO , Cl , Br, I‐, PO43‐ , C2O2‐ ,CH3COO
(Note: Insoluble salts excluded)

2) Detection of ‐ Nitrogen, Sulphur, Chlorine in organic compounds.

G) PROJECTS
Scientific investigations involving laboratory testing and collecting information from other sources.

A few suggested projects are as follows:

  • Checking the bacterial contamination in drinking water by testing sulphide ion
  • Study of the methods of purification of water.
  • Testing the hardness, presence of Iron, Fluoride, Chloride, etc., depending upon the regional
    variation in drinking water and study of causes of presence of these ions above permissible
    limit (if any).
  • Investigation of the foaming capacity of different washing soaps and the effect of addition of
    Sodium carbonate on it.
  • Study the acidity of different samples of tea leaves.
  • Determination of the rate of evaporation of different liquids Study the effect of acids and
    bases on the tensile strength of fibres.
  • Study of acidity of fruit and vegetable juices.

Note: Any other investigatory project, which involves about 10 periods of work, can be chosen with the approval of the teacher.

Practical Examination for Visually Impaired Students of Class 11

Below is a list of practicals for the visually impaired students.

A. List of apparatus for identification for assessment in practicals (All experiments)
Beaker, tripod stand, wire gauze, glass rod, funnel, filter paper, Bunsen burner, test tube, test tube stand,
dropper, test tube holder, ignition tube, china dish, tongs, standard flask, pipette, burette, conical flask, clamp
stand, dropper, wash bottle
• Odour detection in qualitative analysis
• Procedure/Setup of the apparatus

B. List of Experiments A. Characterization and Purification of Chemical Substances
1. Crystallization of an impure sample of any one of the following: copper sulphate, benzoic acid
B. Experiments based on pH
1. Determination of pH of some solutions obtained from fruit juices, solutions of known and varied
concentrations of acids, bases and salts using pH paper
2. Comparing the pH of solutions of strong and weak acids of same concentration.

C. Chemical Equilibrium
1. Study the shift in equilibrium between ferric ions and thiocyanate ions by increasing/decreasing
the concentration of eitherions.
2. Study the shift in equilibrium between [Co(H2O)6]2+ and chloride ions by changing the
concentration of either of the ions.

D. Quantitative estimation
1. Preparation of standard solution of oxalic acid.
2. Determination of molarity of a given solution of sodium hydroxide by titrating it against standard
solution of oxalic acid.

E. Qualitative Analysis
1. Determination of one anion and one cation in a given salt
2. Cations – NH+4
Anions – (CO3)2-, S2-, (SO3)2-, Cl-, CH3COO-
(Note: insoluble salts excluded)
3. Detection of Nitrogen in the given organic compound.
4. Detection of Halogen in the given organic compound.

Note: The above practicals may be carried out in an experiential manner rather than recording observations.

We hope students must have found this information on CBSE Syllabus useful for their studying Chemistry. Learn Maths & Science in interactive and fun loving ways with ANAND CLASSES (A School Of Competitions) App/Tablet.

Frequently Asked Questions on CBSE Class 11 Chemistry Syllabus

Q1

How many units are in the CBSE Class 11 Chemistry Syllabus?

There are 9 units in the CBSE Class 11 Chemistry Syllabus. Students can access various study materials for the chapters mentioned in this article for free at ANAND CLASSES (A School Of Competitions).

Q2

What is the total marks for practicals examination as per the CBSE Class 11 Chemistry Syllabus?

The total marks for the practicals as per the CBSE Class 11 Chemistry Syllabus is 30. It includes volumetric analysis, content-based experiment, salt analysis, class record, project work and viva.

Q3

Which chapter carries more weightage as per the CBSE Syllabus for Class 11 Chemistry?

The organic chemistry chapter carries more weightage as per the CBSE Syllabus for Class 11 Chemistry.