Chemical Bonding class 10

Chemical bonding

A.    Fill in the blanks

1.       The force which holds the two atoms together is called _____________

2.       Transfer of one or more electrons from one atom to other takes place to form ______________or ___________bonds

3.       A _____________covalent compounds shows some ionic character

4.       _____________has four electrons In valence shell.

5.       Elements with completely filled outer shells are called __________

6.       __________compounds  are soluble in water

7.       Negatively charged particles formed by gain of electrons are called_______

8.       Number of electrons present in outermost shell are called __________

9.       The bond formed by a shared pair of electrons with both electrons coming from the same atom.

10.   ____________compounds are hard crystals yet brittle

Short Answer type question

1.           Difference between polar and non polar molecules

2.           Why do most of elements forms ions

3.           What is a lone pair? Give two examples

4.           In the formation of the compound XY₂, an atom X gives one electron to each Y atom. What is the nature of bond in XY₂. Draw the orbit structure of this compound.

5.           The electronic configuration of chloride ion and argon atom is same then what is the difference between the two

6.           What type of bonds are usually formed between the metals and non metals and why?

7.           Elements X,Y and Z have at no 6,9 and 12. Which one will

a.     Form anion                 b) form a cation                  c) has four valence electrons

8.           Predict the type of bonding in

a.     Oxygen                         b. calcium oxide                  c. water

Answer the following

1.     Give reason for the following

a.     A molecule of methane has four single covalent bonds

b.     Sodium chloride has high melting and boiling point

c.      Why atoms loose or gain electrons

d.     Non-polar are soluble in organic solvents but insoluble in water.

2.     Explain with the help of electron dot structure

a.     Formation of water

b.     Formation of Ammonia

3.     Distinguish between Oxidation and Reduction

4.     Five atoms are labeled from A to E

Atoms                        Mass No                    Atomic No

A                                   40                                         20

B                                    19                                         9

C                                      7                                          3

D                                   16                                         8

E                                    14                                         7

         a) Which one of these atoms

                     i)contains 7 protons

                     ii) has an electronic configuration of 2,7

         b) Write down the formula of the compound formed between C and D

         c) Predic  which are i) metals      ii) non-metals

5.     An atom X has electronic configuration of 2,8,18,8,1

         a) predict the sign and charge on a simple ion of X

         b) write if X will be oxidizing agent or reducing agent

6.     What do you understand by redox reaction. Give one example

7.     Give structure of

         a) hydronium ion               b) Ammonium ion

8.     Match the following

                     Column A                                         Column B

1)    Sodium Chloride                                   increases

2)    Ammonium ion                                     Covalent bond

3)    Electronegativity across period        Ionic bond

4)    Carbon tetrachloride                          coordinate bond

5)    Non metallic character down           decreases

the group

Periodic Classification of Elements class 10 ICSE / CBSE

Periodic Classification

(Q.1)  Three elements that have filled outermost shells are

(a) Li, Na, K                  (b) Cu, Ag, Au     (c) He, Ne, Ar       (d) F, Cl, Br
 

(Q.2)  Elements present in the same period have:

(a) Same number of valence electrons.
(b) Same number of shells in their electronic configurations.
(c) No relation with the electronic configuration.
(d) Same number of electrons.
         

(Q.3)  The element having largest atomic sizein second period is

(a) Lithium           (b) Nitrogen                (c) Oxygen              (d) Carbon
 

(Q.4)  The atom of an element has three shells. There are four electrons in its valence shell. The element is

(a) C           (b) Si          (c) Be          (d) Ar
 

(Q.5)  Valency of an element is determined by

(a) The number of electrons present in the outermost shell.
(b) The total number of electrons present in its atom.
(c) The number of shells in an atom. (d) Total number of electrons and protons.
 

(Q.6)  Mendeleev arranged the elements on the basis of

(a) Similarity in physical properties.    (b) Atomic volume
(c) Atomic Number (d) Increasing order of atomic masses and similarity in chemical properties.
 

(Q.7)  Mendeleev’s periodic law states that the properties of elements are the periodic functions of their

(a) Atomic masses           (b) Atomic numbers   (c) Structure (d) Nucleons
 

(Q.8)  Eka aluminium is now known as

(a) Galium  (b) Germanium  (c) Scandium   (d) Silicon
 

(Q.9)  Limitations of the Mendeleev’s Periodic Table were

(a) There was a fixed position assigned to Hydrogen

(b) Existence of isotopes could be explained

(c) There was the exact prediction of elements to be discovered between two elements.

(d) Metals & non metals were not separately positioned.

(Q.9)  Modern Periodic Table is based on
(a) Density of atom        (b) Atomic volume         (c) Atomic number (d) Atomic mass     (Q.10)  Number of groups in the Modern Periodic Table are
(a) 7            (b) 8            (c) 18          (d) 16  (Q.11)  Number of periods in the Modern Periodic Table are

(a) 7            (b) 18                   (c) 8            (d) 32
 

(Q.12)  Elements present in the same group have

(a) Same number of valence electrons.       (b) Same number of electrons as the group number.
(c) No relation with the valence electrons.(d) Valency equal to the group number.
 

(Q.13)  Whenwe move from Li to Rb

(a) Number of shells increase  (b) Number of shells decrease
(c) Number of shells remain same     (d) Number of electrons decreases
 

(Q.14)  Which of the following statements is false about the trends when going from left to right across the periods of the periodic table?

(a) The elements become less metallic in nature. (b) The number of valence electrons increases.
(c) The atoms lose their electrons more easily.  (d) The oxides become more acidic.
 

(Q.15)  Maximum number of elements in a particular period depends on

(a) How electrons are filled into various shells.             (b) The formula 2n²
(c) Our own convenience                   (d) Average atomic mass
 

(Q.16)  Atomic size / radius
(a) Increases as we move from left to right along a period. (b) Decreases as we move from top to bottom along a group. (c) Decreases till we reach the middle and then start increasing along a period. (d) Decreases as we move from left to right along a period.   (Q.17)  Metallic character of elements

(a) Increases from left to right in a period 

(b) Decreases on moving down the group
(c) Increases on moving down the group

(d) First increases then decreases towards the end on moving from left to right in a period. (Q.18)  Element X forms a chloride XCl2, which is a solid with a high melting point. X would most likely be in the same group of the periodic table as:

(a) Mg         (b) Na         (c) Al          (d) Si
 

(Q.19)  A zig-zag line separates the metals from non-metals almost in the middle of the modern periodic table.The elements placed on borderline are known as
(a) Representative elements     (b) Transition elements  (c) Semi-metals (d) Rare earth elements  (Q.20)  The element having largest atomic size among the following is

(a) Hydrogen        (b) Sodium (c) Cesium  (d) Potassium
 

(Q.21)  By considering their position in the periodic table, which one of the following elements would you expect to have the maximum metallic charecter?

(a) As                   (b) Ge         (c) Ga          (d) Be
 

(Q.22)  Name two elements you would except to show chemical reactions similar to magnesium. What is the base for your choice?
(Q.23)  Oxides of elements of group1are:

(a) Acidic    (b) Basic     (c) Neutral            (d) Amphoteric     

(Q.24)  Which of the following is not a noble gas?

(a) Helium  (b) Fluorine (c) Argon    (d) Neon
 

(Q.25)  How many elements were known when Mendeleev started his work?

(a) 60          (b) 63                   (c) 67    (d) 72
 

(Q.26)  In an atom electrons are arranged in shells. These shells are represented by the symbols:

(a) K, L, M....       (b) A, B, C....       (c) P, Q, R....        (d) X,Y,Z....
 

(Q.28)  Atomic size of atom refers to:

(a) Radius of an atom    (b) Volume of an atom  (c) Surface area of an atom
(d) Density of an atom

(Q.29)  In the following diagram for the first three periods of the periodic table, five elements have been represented by the letters a, b, c, d ande (which are not their chemical symbols):

(i)Select the letter which represents a halogen.      

(ii)Select the letter which represents a noble gas.
(iii)What type of bond is formed between a and b                                                                                   (iv)What type of bond is formed between c and d?
(v)Which element will form a divalent anion?