ICSE Class 10

General instructions: Answer all questions. Marks are shown in brackets [ ].

Objective

1. 1.
   What is the cause of chemical combination?

   1. A. The tendency of elements to lose or gain protons to achieve stability.
   2. B. The tendency of elements to acquire the nearest noble gas configuration in their outermost orbit to achieve stability.
   3. C. The attraction between oppositely charged ions formed by electron transfer.
   4. D. The sharing of electrons between metals to form metallic bonds.
   [1]
2. 2.
   What are the electrons present in the outermost shell of an atom called?

   1. A. Core electrons
   2. B. Valence electrons
   3. C. Free electrons
   4. D. Bonding electrons
   [1]
3. 3.
   Which term describes the process where molecules gain or lose electrons to form ions?

   1. A. Dissociation
   2. B. Ionisation
   3. C. Neutralisation
   4. D. Polymerisation
   [1]
4. 4.
   Which charged particles attract one another to form electrovalent compounds?

   1. A. Protons and neutrons
   2. B. Cation and anion
   3. C. Electrons and protons
   4. D. Neutrons and electrons
   [1]
5. 5.
   Negative ions are known as

   1. a. Cations
   2. b. Fermions
   3. c. Anions
   4. d. None of these
   [1]
6. 6.
   What is the meaning of a lone pair of electrons?

   1. A. A pair of valence electrons that is not shared with another atom and remains localized on one atom.
   2. B. A pair of electrons that is shared equally between two atoms in a covalent bond.
   3. C. A single unpaired electron that participates in bond formation with another atom.
   4. D. A pair of electrons found in the innermost shell of an atom, not involved in bonding.
   [1]
7. 7.
   The table shows the electronic configuration of four elements.

   Element	Electronic configuration
   W	2, 6
   X	2, 8
   Y	2, 8, 1
   Z	2, 8, 7

   Which pair of atoms will form a covalent compound?

   1. a. Two atoms of W.
   2. b. Two atoms of X.
   3. c. An atom of W and atom of X.
   4. d. An atom of Y and an atom of Z.
   [1]
8. 8.
   Which of the following correctly defines a coordinate bond and states the conditions necessary for its formation?

   1. A. A coordinate bond is a covalent bond where both atoms share electrons equally, and it forms when both atoms have lone pairs of electrons.
   2. B. A coordinate bond is a type of covalent bond where the shared pair of electrons comes from only one atom (donor), and it forms when the donor has a lone pair and the acceptor has an empty orbital.
   3. C. A coordinate bond is an ionic bond where one atom donates an electron to another, and it forms when the acceptor atom has a high electronegativity.
   4. D. A coordinate bond is a metallic bond where electrons are delocalized, and it forms when both atoms have partially filled orbitals.
   [1]
9. 9.
   Carbon tetrachloride (CCl₄) is classified as which type of covalent molecule?

   1. A. Polar
   2. B. Non-polar
   3. C. Ionic
   4. D. Metallic
   [1]
10. 10.
    An element L consists of molecules. What type of bonding is present in the particles that make up L?

    1. A. Ionic bonding
    2. B. Metallic bonding
    3. C. Covalent bonding
    4. D. Hydrogen bonding
    [1]
11. 11.
    Compare the properties of chlorine atom (Cl) and chloride ion (Cl⁻). Which of the following statements correctly describes a key difference between them?

    1. A. Chlorine atom is colourless and odourless, while chloride ion is yellowish green and poisonous.
    2. B. Chlorine atom has a complete valence shell and is chemically inactive, while chloride ion has an incomplete valence shell and is chemically active.
    3. C. Chlorine atom is yellowish green, poisonous, and chemically active, while chloride ion is colourless, non-poisonous, and chemically inactive.
    4. D. Chlorine atom exists independently and is odourless, while chloride ion does not exist independently and has a suffocating odour.
    [1]
12. 12.
    Why are ionic compounds stable?

    1. A. The electrostatic force of attraction between oppositely charged ions is much stronger than the repulsive force between ions of like charges.
    2. B. Ionic compounds are stable because they share electrons equally between atoms.
    3. C. The stability arises from the weak van der Waals forces between ions.
    4. D. Ionic compounds are stable due to the presence of metallic bonds between ions.
    [1]
13. 13.
    An element A has the electronic arrangement 2, 8, 2, and element B has the electronic configuration 2, 8, 7. When A and B combine to form an ionic compound, what is the correct formula of the resulting compound?

    1. A. AB
    2. B. A₂B
    3. C. AB₂
    4. D. A₂B₃
    [1]
14. 14.
    (a) The one which is composed of all the three kinds of bond [ionic, covalent and coordinate bond]

    1. A. Sodium chloride
    2. B. Ammonia
    3. C. Carbon tetrachloride
    4. D. Ammonium chloride
    [1]
15. 15.
    Polarity of a molecule depends on its ... difference.

    1. a. size difference
    2. b. electron affinity
    3. c. electropositivity
    4. d. electro-negativity
    [1]
16. 16.
    (a) The one which is composed of all the three kinds of bond [ionic, covalent and coordinate bond]

    1. A. Sodium chloride
    2. B. Ammonia
    3. C. Carbon tetrachloride
    4. D. Ammonium chloride
    [3]
17. 17.
    $NH_3$ and $BF_3$ form adduct readily because they form

    1. a. co-ordinate bond
    2. b. covalent bond
    3. c. ionic bond
    4. d. hydrogen bond
    [1]
18. 18.
    Refer to the table showing chlorides and oxides of elements across a period. What is the observed trend in bonding type in chlorides as we move from Group I to Group VII?

    1. A. The bonding type shifts from ionic to covalent due to decreasing electronegativity differences.
    2. B. The bonding type remains purely ionic throughout all groups due to stable electron transfer.
    3. C. The bonding type becomes metallic as the elements gain more electrons across the period.
    4. D. The bonding type shifts from covalent to ionic because electronegativity increases across the period.
    [1]
19. 19.
    Complete the following table for the chlorides of Sodium, Phosphorus, and Carbon by selecting the correct set of answers:

    	Sodium	Phosphorus	Carbon
    Formula of chloride	?	?	?
    Nature of bonding	?	?	?
    Physical state of chloride	?	?	?

    1. A. NaCl, PCl₃, CCl₄; Ionic, Covalent, Covalent; Solid, Liquid, Liquid
    2. B. NaCl₂, PCl₅, CCl₂; Ionic, Ionic, Covalent; Solid, Solid, Gas
    3. C. NaCl, PCl₃, CCl₄; Covalent, Covalent, Ionic; Gas, Liquid, Solid
    4. D. Na₂Cl, PCl₃, CCl₄; Ionic, Covalent, Covalent; Solid, Gas, Solid
    [1]
20. 20.
    The electronic configuration of nitrogen is 2,5. How many electrons in the outer shell of a nitrogen atom are **not** involved in the formation of a nitrogen molecule (N₂)?

    1. A. Zero
    2. B. One
    3. C. Two
    4. D. Three
    [1]