ICSE (Class X)
Syllabus (2013)
Subject: Science (Chemistry) Paper - 2
Class: X
There will be one paper of one and a half-hours duration of 80 marks and
Internal Assessment of practical work carrying 20 marks.
The paper will be divided into two sections, Section I (40 marks) and Section
II (40 marks).
Section I (compulsory) will contain short answer questions on the
entire syllabus.
Section II will contain six questions. Candidates will be required to
answer any four of these six questions.
Note: All chemical process/reactions should be studied with reference
to the reactants, products, conditions, observation, the (balanced) equation and
diagram.
1. Periodic Properties and variations of Properties – Physical and Chemical.
(i) Periodic properties and their variations in groups and periods.
Definitions of following periodic properties and trends in these properties
in groups and periods should be studied: atomic size, metallic character
non-metallic character ionisation potential electron affinity
electronegativity
(ii) Periodicity on the basis of atomic number for elements.
Relation between atomic number for light elements (proton number) and atomic
mass for light elements; the modern periodic table up to period 3 (students to
be exposed to the complete modern periodic table but no questions will be asked
on elements beyond period 3 – Argon); periodicity and other related properties
to be described in terms of shells (not orbitals); special reference to
the alkali metals and halogen groups.
2. Chemical Bonding
Electrovalent, covalent and co-ordinate bonding, structures of various
compounds – orbit structure and electron dot structure.
Definition of Electrovalent Bond.
Structure of Electrovalent compounds NaCl, MgCl2, CaO;
Characteristic properties of electrovalent compounds – state of existence,
melting and boiling points, conductivity (heat and electricity), ionisation in
solution, dissociation in solution and in molten state to be linked with
electrolysis.
Covalent Bond – definition and examples, structure of Covalent molecules on
the basis of duplet and octet of electrons (example : hydrogen, chlorine,
nitrogen, water, ammonia, carbon tetrachloride, methane.)
Characteristic properties of Covalent compounds – state of existence, melting
and boiling points, conductivity (heat and electricity), ionisation in solution.
Comparison of Electrovalent and Covalent compounds.
Definition of Coordinate Bond: The lone pair effect of the oxygen atom of the
water molecule and the nitrogen atom of the ammonia molecule to explain the
formation of H3O+ and OH- ions in water and NH4 + ion. The meaning of lone pair;
the formation of hydronium ion and ammonium ion must be explained with help of
electron dot diagrams.
