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ICSE Guess > ICSE Papers > Important Questions > Class X > 2008 > Chemistry > Chemistry By :- M. P. Keshari

Q. 1. State the no. of elements in period 1, period 2 and period 3 of the periodic table.

Q. 2. Name the elements in period 1.

Q. 3. What happens to atomic size of elements on moving from left to right in a period?

Q. 4. State the common feature of the electronic configuration of elements at the end of period 2 and 3.

Q. 5. If an element is in Group 7 [or Group 7 A] is it likely to be metallic or non-metallic character.

Q. 6. Supply the missing word from those in brackets : If an element has one electron in its outermost energy level [shell] then it is likely to be ______________ [metallic/non-metallic].

Q. 7. Complete the sentence choosing the correct word/s from those given in brackets.

1. The properties of the elements are a periodic function of their ____________ [atomic number, mass number, relative atomic mass.]
2. Moving across a ________ of the Periodic Table the elements show increasing ________ character [group, period, metallic, non-metallic]
3. The element at the bottom of a group would be expected to show _____________ metallic character than the element at the top [less, more]
4. The similarities in the properties of a group of elements is because they have the same _________ [electronic configuration, number of outer electrons , atomic numbers.]

Q. 8. What is meant by a Group in the Periodic Table. Within a Group where would you expect to find the element with

1. The greatest metallic character,
2. The largest atomic size.

Q. 9. State whether the ionization potential increases or decreases on going down a Group.

Q. 10. How many elements are there in Period 2.

Q. 11. Name the gas which is the most electronegative among all the elements.

Q. 12.With reference to the first three periods of the modern periodic table answer the following questions :

1. Write the formula of the sulphate of the element with atomic number 13.
2. What type of bonding will be present in the oxide of the element with atomic number 1.
3. Which feature of the atomic structure accounts for the similarities in the chemical properties of the elements in group 7A of the periodic table.
4. Name the element which has the highest Ionisation potential.
5. How many electrons are present in the valency shell of the element with the atomic number 18.
6. What is the electronic configuration of the element in the third period which gains one electron to change into an anion.

Q. 13. What is the name given to the energy released when an atom in its isolated gaseous state accepts an electron to form an anion.

Q. 14. 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.

Q. 15. Predict the group of an element X if its atomic number is 16.

Q. 16. The elctronegativities (according to Pauling) of the element in period 3 of the Periodic Table are as follows : Al [1.5] Cl [3.0] Mg [1.2] Na [0.9] P [2.1] S [2.5] Si [1.8] Arrange the elements in the order in which they occur in the Periodic Table from left to right. [The group 1 element first, followed by group 2 element and so on, up to group 7.]

Q. 17. Choose the word/phrase from the brackets which correctly completes each of the following statements :

1. The element below sodium in the same group would be expected to have a ______ [lower/higher] electronegativity than sodium and the element above chlorine would be expected to have a _________ [lower/higher] Ionisation potential than chlorine.
2. From the left to right in a given period, the number of shells [remains the same / increases / decreases].
3. Down a group, the number of valence electrons [remains the same / increases decreases].

Q. 18. (i) to(v)refer to changes in properties of elements on moving left to right across a period of the Periodic Table. For each property, choose the letter corresponding to the correct answer from A,B,C & D.

1. Non-metallic character of elements ______ A: decreases. B: increases. C: remains same. D: depends on period.
2. (ii) The electronegativity ________ A: depends on the number of valence electrons. B: remains the same. C: decreases. D: increases.
3. (iii) The ionization potential ________ A: goes up and down. B: decreases C: increases. D: remains the same.
4. Atomic size _________ A: decreases. B: increases. C: remains the same. D: sometimes increases or decreases.
5. The electron affinity of the elements in group 1 to 7 ________ A: goes up and down. B: decreases and then increases. C: increases. D: decreases

. Q. 19. The element of one short period of the Periodic Table are given below in order from left to right :- Li, Be, B, C, O, F, Ne.

1. To which period do these elements belong. Which is the missing element and where should it be placed.
2. Which element exhibits catenation. Place the element F, Be & N in order of increasing electronegativity.
3. Which one of the above elements belongs to the halogen series.