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PERIODIC TABLE

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Short answer questions

1 1. Name the scientist who presented ‘law of octaves.’

2 2. Name the scientist who presented modified periodic table.

3. Which is the shortest period in the long form of periodic table?

4. Which is the longest period in the long form of periodic table?

5. Which element has the highest ionization enthalpy value?
6. Which element has the highest negative electron gain enthalpy value?

   7. Which element has the highest electro negativity?
   8. Which is the most electropositive element in the periodic table?
   9. Why the electron gain enthalpies of halogens are so high?
   10. Why noble gases have positive electron gain enthalpies?
   11. Why the second ionization enthalpy of an element is higher than the first?

12. What property of an element is measured by its electron afficnity?

13. The elements of group 17 are F, Cl, Br and I. which of these elements will form negative ions most readily and why?

14. Why do group 1 elements show similar chemical properties/

15. The atomic number of an element X is 3. Identify the group and the period in which X is present.

16. Why does the atomic size decrease on moving from left to right across a period of the periodic table?

17. What happens to the metallic character of the elements as we move down in a group of the periodic table?

18. Why do the elements placed in the same group of the periodic table have similar chemical properties?

19. Element X forms a diatomic molecule. An atom of X requires one electron to form a stable X- ion. In which group of the periodic table is this element present?

20. How does the valency of an element vary on moving from left to right across a period of the periodic table?

21. Name an element from the following set of elements which does not belong to the set and explain why it does not belong to the set: Ca, Mg, Na & Be.

Long answer questions

1. What do you understand by periodicity of properties? What is its cause?

2. Define atomic radius. How does it vary in a group and in a period?

3. What do you understand by ionization potential of an atom? Which factors influence the magnitude of ionization potential?

4. How does ionization potential vary in a group and in a period?

5. Explain the following giving reasons:

noble gases have very high value of I.P

6. Define electron affinity. How does it vary in a group and in a period?

7. Explain the following:

a. Noble gases have practically zero electron affinity.

b. Halogens have very high values of electron affinity.

c. Fluorine has lower electron affinity than chlorine.

8 8. Define electronegativity. On what factors, does it depend?

      9. How does electronegativity vary in a group and in a period?
     10. On the basis of E.N, how will you predict about the magnitude of polarity in a covalent bond
     11. a. Name the first and last element in period 3

b. Which element in period 3 is likely to react most violently with chlorine?

c. Out of the eight elements in period 3, name a metal that is likely to form a compound of the formula XCl3, with chlorine.
12. The elements of the third period in the periodic table are Na, Mg, Al, Si, P, S & Cl. Which of these elements

a. exists as diatomic molecules at room temperature and pressure?

b. has the largest first I.P?

c. is the most metallic in nature?

d. has the highest electrical conductivity?

e. has the highest E.A?
13. Nitrogen and Phosphorus belong to group 15 of the periodic table. Write the electronic configuration of these two elements. Which of these will be more electronegative? Why?
14. The following table represents a part of the periodic table:
                                   Li            Be               B         C         N          O           F
                                   Na          Mg              Al        Si         P          S          Cl
   Answer the following questions on the basis of this table:
a. Which element has the smallest atomic size?
b. Which element has the largest at.size?
c. Which element has highest I.P?
d. Which element would form +1 ion’s?
e. Which element have outermost e.configuration of 7?
f. which elements r alkali metals?
g. which element has the lowest E.N?
15. The elements Na, Mg, Al, Si, P, S, Cl & Ar are arranged in the periodic table in the increasing order of their at.no's
        a. Which element is the most E.N?
       b. Which element is the electropositive?
        c. Which element is the least reactive?
        d. Which element is the most abundant element?
       e. Which elements are gases at room temperature?
16. The table given below represents the first three perio0ds of the modern periodic table. Study the table and answer the questions that follow:
            a. Which of the lettered elements is an inert gas?

b. State two of the lettered elements which are in the same group.

c. Give the name and position of the lettered halogen element in the table.
d. Which one of the lettered elements would you expect to react violently with chlorine?

e. How many electrons are present in v.shell of an element E with at.no 18?
f. What is the name given to the energy released when an atom in its isolated state accepts an electron to form an anion?
17. Give below is a part of P.T
               Li            Be             B         C         N          O          F
               Na        Mg            Al        Si         P          S          Cl
As we move horizontally from left to right in period,
a. what happens to the metallic character of the elements?
b. what happens to the atomic size?

       18. Given below are some elements with their atomic radii:
             element                        Cs              Li         K         Rb       Na
           Atomic radius             2.25            1.34     1.96     2.11     1.54
         infer to which group of the periodic table do they belong and how does the atomic radii vary from top to bottom of the periodic table.

Given below is a list of symbols of elements from the periodic table:
                  S, Al, C, Ar, Mg, F, O & B.
Choose from the above list, the symbol for
a. most metallic element.              b. the most E.N element.
c. a noble gas.                                 d. the elements of group 16 of the p.table.
e. the elements of period 3 of the periodic table.

     19. X, Y and Z are in the third period of the periodic table. X forms an acidic oxide, Y forms a basic oxide and Z forms an amphoteric oxide.
        a. arrange the elements X, Y & Z in the increasing order of their atomic numbers.
        b. name the most metallic element.
        c. in which group of the periodic table, Z is likely to be present?

   20. A part of the periodic table is shown below
                  I            II         III        IV        V         VI        VII      0
                 H                                                                            He
                 A                                                                     B
                 C                                                                     D
        Answer the following regarding – A, B, C and D:
    a. the most metallic element.                              b. the mot non metallic element.
    c. the most electronegative element.               d. the element having the highest E.A.

    21. The position of three elements A, B and C in the periodic table are shown below:   Group 16           Group 17
                        -                             -
                        -                           A
                        -                            -
                        B                          C
   a. State A is a metal or a non metal.
     b. State whether C is more reactive or less reactive than A.
   c. will C be larger or smaller in size than B?
     d. which type of ion, cation or anion, will be formed by element A?

22. Elements X, Y and Z belong to the third period of the periodic table. Their ionization potential varies as Y>X>Z.

a. the atomic number of X is _________(more/less) than that of Y but _______(more/less) than that of Z.

b. X is likely to be more E.N than __________________(Y/Z).

c. the atom of element Z would be expected to be ______________________ (larger/smaller) than the atom of the element Y.
d. the atom of elements X, Y & Z have ______________(same/different) number of valence electrons.

Conceptual questions

1. The table shows a part of periodic table, with some elements inserted in their positions. Answer the following questions:

a. Name a transition element.
b. Name two more elements in the same group.

c. Name the elements whose oxide is basic.

d. Give the atomic number of three elements which form halogen group.

e. How many atoms of element 35 will combine with one atom of element number 20?

f. Name two elements in the same period.
g. Give the atomic number of two elements which are inert in nature.

2. An element A ha an atomic number 11.

a. Represents its electronic configuration.

b. To which group of periodic table, does it belong?

c. What is its Valency?

d. Write the formula of its oxide.

3. The table given below shows the mass number of neutrons in four elements P, Q, R and S.

Elements	P	Q	R	S
Mass number	12	20	23	35
Number of neutrons	6	10	12	18

a. Write down the atomic number of S.

b. Write down the electronic configuration of S.

c. To which group, does S belong?

d. To which period, does S belong/

e. What will be the nature(ionic or covalent) of compound formed by (i) R and S? (ii) P and S?

4. Among the elements given in the list below, pick out the element which is (i) most electropositive (ii) Most E.N (iii) a noble gas.
Li, Be, B, C, N, O, F, Ne, Mg, Al, Si, P, S, Cl, K, Ca, C

5. The atoms A and B have electronic configuration (2,8,18,2) and (2,6) respectively.

a. To which periods, do A and B belong?

b. To which groups, do A and B belong?

c. What is the valency of A and B with respect to hydrogen?

d. What is the formula of compound of A and B? Is the compound ionic or covalent in nature?

Previous Year’s ICSE Examination Questions

Short Answer Questions

1. (a) i. Across a period, the I.P __________ii. Down the group, E.A _________

(b) Give the number of the group and the period of the element having three shells with three electrons in valence shell.

(c) The oxidizing power of elements increases from left to right along a period in the periodic table.

2. a) What is the common feature of the electronic configuration of the elements at the end of period 2 and period 3?

(b) If an element is in Group 17, it is likely to be metallic or non metallic in character?

3. a) Give the number of elements in period 1, period 2, period 3 of the periodic table.

(b) Name the element in the Period 1.

(c) What happens to the atomic size of the elements on moving from left to right across the period?

4. The electronegativities of the elements in period 3 of the periodic table, with the elements arranged in the alphabetical order are as follows

Element Al Cl Mg Na P S Si

E.N 1.5 3.0 1.2 0.9 2.1 2.5 1.8

Arrange the elements in the order in which they occur in the periodic table from left to right.

Long Answer Questions

1. An element has an atomic number 16, State:

a. The period to which it belongs

b. The number of valence electrons.

c. Whether it is a metal or non metal.

2. Define the following terms: I.E and E.A

3. a) The following questions refer to the periodic table:

(i) Name the first and the last element in period 2.

(ii) What happens to the atomic size of elements on moving from top to bottom in a group?

(iii) Which of the element has the greatest electron affinity among the halogens?

(iv) What is the common feature has of the electronic configurations of the elements in group 17?

(b) Supply the missing word from those in the brackets. (do not write the out the sentence)

(i) If an element has a low ionization energy then it is likely to be______(metallic/nonmetallic)

(ii) If an element has seven electrons in its outermost sheel then it is likely to have the _____(largest/smallest) atomic size among all the elements in the elements in the same period.

(c) (i) The metal of group 2 from top to bottom are: Be, Mg, Ca, Sr, Ba. Which of these metals will form ions most readily and why?

(ii) What property of an element and neon is the last element is measured by electro negativity?

4. A group of elements in the periodic table is given below:

Boron, aluminum, gallium, indium, and thallium.

(boron is the first member of the group and thallium is the last)

Answer the following questions in relation to the above group of elements:

(a) Which element has the most metallic character?

(b) Which element would be expected to have the highest electrone gativity?

(c) If the electronic configuration of aluminum is 2, 8, 3, how many electrons will be there in the outermost shell of thallium?

(d) The atomic number of boron is 5. Write the chemical formula of the compound formed when boron reacts with chlorine.

(e) Will the elements in the group to the right of this boron group be more metallic or less metallic in character? Justify your answer.

5. The elements of one short period of the periodic table are given bellow in order from left to right: Li, Be, B, C, O, F and Ne.

(a) To which period, do these elements belong?

(b) One element of this period is missing. Which is the missing element and where should it be placed?

(c) Which one of the elements in this period shows the property of catenation?

(d) Place the three elements, beryllium and nitrogen, in the order of increasing electronegativity.

(e) Which one of the above elements belongs to the halogen series?

6. Parts (a) to (e) refer to changes in the properties of elements on moving from left to right across a period of the periodic table. For each property, change the letter corresponding to the correct answer from the choice A,B, C and D.

(a) The non- metallic character of the elements

(i) Decreases. (ii) Increases.
(iii) Remains the same. (iv) Depends on the period.

(b)  The electronegativity
(i)  Depends on the number of electrons.    (ii) Remains the same.
(iii) Decreases.                                                    (iv)Increases.

c) The ionisation potential

i) Goes up and down. (ii) Decreases and then increases.
(iii) Increases. (iv)Decreases.

(d) The atomic size

(i) Decreases (ii) Increases
(iii) Remains the same (iv) Sometimes increases sometimes decreases.

(e) The electron affinity of the elements in group 1 to 7

(i) Goes up and then down. (ii) Decreases and then increases.
(iii) Increases. (iv) Decrease.

7. Choose the word or phrase from the bracket which correctly completes each of the following statements:

(a) The elements below sodium in the same group would be expected to have a ______________(lower/higher) electronegaivity than sodium and the element above chlorine would be expected to have a ______(lower/higher) ionization potential than chlorine.

(b) On moving from left to right in a period the number of shells __________(remains the same /increases/decreases).

c) On moving down a group the number of valence electrons_________(remains the same/increases/decreases).

8. You are provided with the first three periods of the Modern periods tables. Study the table and answer the questions that follow:

(a) Write the formula of the sulphate of element with atomic number 13.

(b) What type of bonding will be present in the oxide of element with atomic number one?

(c) Which feature of the atomic structure for the similarities in the chemical properties of the elements in group 17 of the periodic table?

(d) Name the element that has the highest ionization potential.

(e) How many electrons are present in the valence shell of an element with atomic number 18?

(f) What is the term given to the energy when an atom, in this isolated gaseous state, accept an electron to from an anion?

(g) What is the electronic configuration of the third period that gains one electron to change into an anion?

(h) Fill in the blanks.

The atomic size _______as we move from left to right across the period because the ________increases but the ________remains the same.

9.(a) What is meant by a group in the periodic tables?

(b) Within a group, where would you find the element with

(i) The greatest metallic character?

(ii) The largest atomic size?

(c ) State whether the ionization potential increase or decreases on going down a group.
(d) How many elements are there in period 2?

10. Copy and complete the following sentences choosing the correct words (s) from the words given in brackets at the end of each sentence:

(a) The properties of the elements are periodic functions of their___________(atomic numbers, mass numbers, relative atomic masses).

(b) Moving across a____________ of the periodic table, then elements show increases __________

Metallic character than the elements at the top (period, group, metallic, non- metallic)

(c) The element the bottom of group would be expected to show__________ metallic character than the elements at the top (less, more)

(d) The similarities in the properties of a group of elements are because they have the same_________ (electronic configuration, number of outer electrons, atomic numbers).

Objective Questions

1. Fill in the blanks.

(i) If an element has a low inisation energy, then it is likely to be __________ (metallic/non-metallic).
(ii) If an element has seven electrons in its outermost shell, then it is likely to have the _____ (largest / smallest) atomic size among all the elements in the same period.
(iii) Element E has an electronic configuration of (2,8,8,18,1) mention the type of atom ( metallic or non metallic)

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Tuesday, 28 May 2013

VIDEOS OF ORGANIC NAMED REACTIONS & PROBLEMS BASED ON SPECTROSCOPY

Sunday, 28 April 2013

LIST OF Ph D ENTRANCE EXAMS IN CHEMISTRY

ENTRANCE EXAM OPTIONS FOR CHEMISTRY

S.NO ENTRANCE EXAM NAME LAST SUBMISSION DATE

1 GATE 8 -OCT-12 20-JAN-13

2 CSIR UGC NET June/ Dec

3 IISc (Ph.D.) 21-Mar-12 29-Apr-12

4 TIFR 19-Oct-12 9-Dec-12

5 ISM (Indian Institute of Mines) 06-Apr-12 30-May-12

6 Jamia Millia Islamia university 9-Jul-12 28-Jul-12

7 Jamia hamdard university NET Qualified Candidates

8 (BHU)/CRET 25-Jun-12 8-Jul -12

Direct Admission: Candidate qualified in NET-JRF / NET-LS

(without fellowship) / GATE / SLET

9 AMU (Aligarh Muslim University) 6 -OCT-12 4-Nov-12

10 BITS Mesra 30-Jul-12 17-Aug-12

11 Rajasthan university(MPAT) Oct-12

12 CUSAT(DAT) 10-Feb date will be announced

13 Pondicherry University 26-apr-12 27-May - 12

14 Hyderabad University 4-May-12 1 to 7June - 12

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