InterviewSolution
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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 3101. |
The balancing of chemical equations is done to satisfy which law |
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Answer» LAW of CONSERVATION of mass |
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| 3102. |
The azimuthal quantam number of an electron is zero , then the shape of its orbitals will be |
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Answer» circular |
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| 3105. |
The average atomic mass of carbon is ………………. . |
| Answer» Solution :12.011 amu | |
| 3106. |
The average atomic mass of an element becomes fractional due to the presence of ……………. . |
| Answer» SOLUTION :ISOTOPES | |
| 3107. |
The automatic darkening of photo chromatic glass is because of the presence of |
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Answer» SILVER bromide |
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| 3108. |
The atomsof the 'group zero ' elementsare unreactive becausein their valence shell they have _____________. |
| Answer» SOLUTION :STABLE ELECTRONIC | |
| 3109. |
The atoms of elements beloning to the same group of periodic table have the same |
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Answer» NUMBER of protons |
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| 3110. |
The atoms of certain elements such as hydrogen, oxygen and nitrogen have independent existence. |
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| 3111. |
The atoms lose or gain electrons to achieve a noble gas electronic configuration. Do you agree ? |
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| 3112. |
Select whether the statement is true or false.The atomicity of phosphorus is four. |
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| 3114. |
The atomicity of K_(2)Cr_(2)O_(7) is ……………. . |
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Answer» 9 |
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| 3115. |
The atomic Size of th elements in a period increases from left to right . |
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Answer» |
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| 3116. |
The atomic size of beryllium is smaller than the atomic size of lithium. Give reason. |
| Answer» Solution :In lithium (atomic NUMBER = 3) the outermost electron of L-shell is attracted by 3 protons. But in beryllium (atomic number = 4) the outermost ELECTRONS of L-shell are attracted by 4 protons. That is, the electrons of L-shell are attracted STRONGLY TOWARDS the nucleus in case of beryllium as compared to lithium. THEREFORE, the atomic size of beryllium is smaller than the atomic size of lithium. | |
| 3117. |
The atomic size of lithium is ________ than that of sodium. (greater/smaller). |
| Answer» SOLUTION :SMALLER | |
| 3118. |
The atomic size decreases in a period on moving from left to right. |
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Answer» Solution :As moving from left to right in a period, the atomic number of elements increases by 1. As atomic number increases, nuclear charge also increases. Due to this increased nuclear charge, the ELECTRONS are ATTRACTED strongly TOWARDS the NUCLEUS and hence the atomic size decreases. |
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| 3119. |
The atomic radius of non-metallicelements is known as ________. |
| Answer» SOLUTION :COVALENT RADIUS | |
| 3120. |
The atomic radius decreases from Li to B |
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Answer» |
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| 3121. |
The atomic radii of three elements A, B and C of a periodic table are 186 pm, 104 pm and 143 pm respectively. Giving a reason, arrange these elements in the increasing order of atomic numbers in the period. |
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Answer» SOLUTION :Order of atomic NUMBER of element is as follows: `AltCltB` Because atomic SIZE generally decreases along a period, so B has the HIGHEST atomic number followed by C and A. |
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| 3122. |
The atomic radii of first group elements are given below: State the reason behind the observed trend in the above elements. |
| Answer» SOLUTION :NEW SHELLS are being added, so the distance between the NUCLEUS and outermost electron increases. | |
| 3123. |
The atomic radii of first group elements of the Periodic Table are as follows: (i) Arrange these elements in the increasing order of their atomic radii. (ii) Name the elements which have the smallest and the largest atoms.(iii) How does the atomic size vary as you go down a group? |
Answer» SOLUTION : (II) The element Li has the smallest ATOM (atomic RADIUS 152 pm) whereas the element Cs has thelargest atom (atomic radius 262 pm). (III) From this arrangement, we find that the atomic size (or radius) increases down the group. |
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| 3124. |
The atomic numbers of two elements are 8 and 16 respectively. Write the electronic configuration of these two elements. Do you keep these two elements in the same group of the modern periodic table? Justify your answer. Find out which of these two elements is more electronegative. Give reason for your answer. |
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Answer» Solution :Atomic number: 8 Electronic Configuration : 2, 6 Atomic number: 16 Electronic Configuration : 2, 8, 6 Same number of valence electrons THEREFORE in the same group. Electronegativity is the tendency of an atom to attract SHARED pair of electrons towards itself. Electronegativity decreases down the group. Therefore, oxygen is more ELECTRONEGATIVE than sulphur. |
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| 3125. |
The atomic numbers of two elements A and B are 11 and 12 respectively. Which element exhibits highest metallic property ? Why ? Write the molecular formula of the compounds formed when these elements combine with the element 'Z' having atomic number 8. |
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Answer» Solution :A Because as the effective NUCLEAR charge ACTING on the valence shell electrons increases across a period, the TENDENCY to lose electrons will DECREASE. 
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| 3126. |
The atomic numbers of three elements A, B, and Care 12, 18, and 20 respectively. State, giving reason, which two elements show similar properties. |
| Answer» Solution :Electronic configurations are: `A (12) to 2, 8, 2, B (18) to 2, 8, 8, and C (20) to 2, 8, 8, 2`. Since ELEMENTS A and C have two valence electrons each, they SHOW similar properties. | |
| 3127. |
The atomic numbers of three elements A, B and C are 12, 18 and 20 respectively. State giving reason, which two elements will show similar properties. |
| Answer» Solution :A and C will show SIMILAR PROPERTIES because they have same NUMBER of VALENCE electrons. | |
| 3128. |
The atomic numbers of nitrogen, oxygen and fluorine are 7, 8 and 9 respectively. Write theelectronic configuration of each element and answer the following questions:(a) Which one of N, O and F is most electronegative and which one is least electronegative? (b) What is the number of valence electrons of F? (c) What is valency of each one of N, O and F? |
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Answer» Solution :Electronic CONFIGURATION of Nitrogen : 2,5 OXYGEN : 2,6 Fluorine : 2,7 (a) Fluorine (F) is most electronegative and nitrogen (N) is least electronegative. (b)Fluorine (F) has 7 valence electrons. (c) Valency of nitrogen is 3 and 5, valency of oxygen is 2, valency of fluorine is 1. |
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| 3129. |
The atomic numbers of four elements P, Q, R and S are 6, 8, 14 and 16 respectively. Out of these, the element known as metalloid is ...... |
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Answer» P |
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| 3130. |
The atomic numbers of four elements A,B,C and D are 6,10,12 and 17 respectively. Which two elements combine to form a covalent compound ? |
| Answer» Answer :A | |
| 3131. |
The atomic numbers of five elements A, B, C, D and E are 6, 8, 3, 7 and 9 respectively. (i) Which is the element having the highest electropositivity among these elements ? Why? (ii) Which is the element having the least metallic character among these elements ? Why? (iii) What is your conclusion about the relationship between metallic character and electropositivity of an element ? |
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Answer» SOLUTION :(i) C. This ELEMENT comes FIRST in the second period / The electropositivity DECREASES along the period / It has only one electron in the outermost shell & can donate electron. (ii) E. This element is towards the END of second period / The metallic character decreases along the period / It accepts electrons. (iii) As the electropositivity increases metallic character also increases. |
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| 3132. |
The atomic numbers of elements A, B, C, D and E are given below : From the above table, answer the following questions - (a) Which two elements are chemically similar ?(b) Which is an inert gas ? (c) Which element belongs to 3^(rd) period of periodic table ?(d) Which element among these is a non-metal ? |
Answer» Solution :The electronic configuration of the elements are as follows :  (a) Elements C and D are chemically similar since they have same number of VALENCE electrons. (B) Element B is an inert gas element since it has complete OCTET. (c) Element C belongs to third period since it has THREE SHELLS. (d) Element A is a non-metal since it has five valence electrons. |
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| 3133. |
The atomic number of tin is 50 and chlorine is 17. What should be the shape of SnCl_(2) molecule in its vapour state? |
Answer» Solution :The electronic configuration of Sn is `1s^(2)2S^(2)2p-.^(6)3s^(2)3p^(6)3d^(10)4s^(2)4p^(6)4d^(10)5s^(2)5p^(2)`and chlorine is `1s^(2)2s^(2)2p^(6)3s^(2)3p^(5)`.Hence, in `SnCl_(2)` molecule in vapour state, there is ONE lone pair of electrons and two BOND pairs of electrons in the valence shell of tin. Therefore, the expected shape is trigonal planar. But due to presence of the lone pair, its shape is bent and bond angle is `88^(@)`.
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| 3134. |
The atomic number of three elements are given below : Write the symbol of the element which belongs to (i) group 13, (ii) group 15, of the periodic table. State the period of the periodic table to which these elements belong. Give reason for your answer. |
Answer» Solution :Electronic configuration of the elements A, B and C are as given :  (i) Element A belongs to group 13 (Group No. = 10 + 3 = 13). It is boron (B) (ii) Element B belongs to group 15 (Group No. = 10 + 5 = 15). It is nitrogen (N) Both these elements BELONG to SECOND PERIOD since they have TWO shells. |
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| 3135. |
The atomic number of three elements are given below : {:("Element(Symbols)",A, B, C),("Atomic number",5,7,10):} Write the symbol of the elements which belongs to (a) group B, (b) groups 15, of the periodic table, state the period of the periodic table towhich these elements belong. Give reason for your answer. |
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Answer» Solution :(a) A BELONGS to group B, because its electronic configuration is 2, 3 i.e, it has 3 valence electrons. (b)Bbelongsgroup15becauseitselectronicconfigurationis2, 5, i.e, it has 5 valence electrons.They belong to `2^(nd)` PERIOD as they both have TWO shells. |
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| 3136. |
The atomic number of three element X, Y and Z are 3, 11 and 17 respectively. State giving reason which two elements will show similar chemical properties. |
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Answer» Solution :X and Y will SHOW similar CHEMICAL PROPERTIES as these have same valence electrons. X = 2, (1) Y = 2, 8, (1) |
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| 3137. |
The atomic number of Na and Mg is 11 and 12 respectively and they belong to the same period. a) Which one would have smaller atomic size. b) Which one would be more electropositive. c) To which group would each one belong. |
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Answer» Solution :a) MG has smaller atomic size due to high nuclear charge (`NA to 2,8,1, Mg to 2.8.2`) b) Na would be more electropositive because it can LOSE the valance electron more easily C) Na belongs to group 1 and Mg BELONG to group 2 as Na contains 1 and My contains 2 valence electron. |
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| 3138. |
The atomic number of helium is 2 and the atomic number of lithium is 3. Is it possible to have an element with atomic number 2.5? |
| Answer» SOLUTION :It is not POSSIBLE because atomic number (number of PROTONS) cannot be a FRACTION. | |
| 3139. |
The atomic number of elements A, B, C, D and E are given below: From the above table, answer the following questions : (i) Which two elements are chemically similar ? (ii) Which is an inert gas ? (iii) Which element belongs to 3 period of periodic table ? (iv) Which element among these is a non-metal ? |
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Answer» SOLUTION :(i) C and D (II) B (III) C (iv) A |
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| 3140. |
The atomic number of element X is 12. [Symbol is not real] Write the subshell wise electronicconfiguration of X. |
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| 3141. |
The atomic number of element X is 12. [Symbol is not real] Write down the molecular formula of the chloride of X. [Hint Valency of CI=1] |
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| 3142. |
The atomic number of element X is 12. [Symbol is not real] Which block does it belong to ? |
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| 3143. |
The atomic number of element X is 12. [Symbol is not real] Which period does this element belong to ? |
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| 3144. |
The atomic number of Cl is 17. On the basis of this information, answer the questions that follow: (a) Write the electronic configuration of Cl. (b) Find the valency. (c) To which group does it belong? (d) Identify the type of ion it will form. (e) Write down the formula of the compound it forms with other elements. |
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Answer» SOLUTION :(a) Electronic configuration of Cl is 2, 8, 7. (b) Valency of Cl is 1 as it requires only one electron to COMPLETE its octet. (c) It belongs to Group 17 of the MODEM Periodic Table. (d) It will form an anion `(CI^(-))` by gaining one electron. (e) It form HCl with Hand NaCl with NA. |
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| 3145. |
The atomic number of beryllium is 4 while that of oxygen is 8. Write down the electronic configuration of the two and deduce their valency from the same. |
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Answer» Solution :ATOMIC number of BERYLLIUM = 4 Electronic configuration= (2, 2) Atomic number of OXYGEN = 8 Electronic configuration= (2, 6) Valency of Beryllium is 2, Valency of Oxygen is = 8 -6 = 2 |
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| 3146. |
The atomic number of an element 'X' is 20. (i) Determine the position of the element 'X' in the periodic table. (ii) Write the formula of the compound formed when 'X' reacts/combines with another element 'Y' (atomic number 8). (iii) What would be the nature (acidic or basic) of the compound formed ? Justify your answer. |
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Answer» Solution :Electronic configuration = 2,8, 8, 2. (i) .X. is PRESENT in the `2^(nd)` group and `4^(TH)` period of the periodic table. (ii) XY. (iii) Basic because X is a metal and the oxides of metals are basic in NATURE (Y, Atomic number = 8, Oxygen). |
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| 3147. |
The atomic number of an element ‘y ’ is 20. The electronic configuration of the ion having inert gas configuration is |
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Answer» 2,8,10 |
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| 3148. |
The atomic number of an element “X' is 20.(i) Determine the position of the element 'X' in the periodic table. (ii) Write the formula of the compound formed when 'X' reacts/combines with another element‘Y' (atomic number 8).(iii) What would be the nature (acidic or basic) of the compound formed? Justify your answer. |
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Answer» Solution : Electronic configuration : 2, 8, 8, 2 (i) .X. is in the 2ND group and 4TH period of the PERIODIC table. (ii) ` UNDERSET(2,8,8,2)(X) + underset(2,6)(Y) to XY` (iii)The nature of the compound formed is basic because X is a metal and Y is oxygen. The oxides of metals are basic in nature. |
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| 3149. |
The atomic number of an element ‘X' is 19.(a) Write its electronic configuration. (b) To which period of the Modern Periodic Table does it belong and what is its valency? (c) If 'X' burns in oxygen to form its oxide, what will be its nature - acidic, basic or neutral? (d) Write balanced chemical equation for the reaction when this oxide is dissolved in water. |
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Answer» SOLUTION :(a) CONFIGURATION of X (19) = 2,8,8,1. (B) It belongs to fourth PERIOD and its valency is 1. (c) BASIC oxide `(X_2O)` (d) `X_2O + H_2O to 2XOH` |
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| 3150. |
The atomic number of an element 'X' is 19. (i) Write its electronic configuration. (ii) To which period of the Modern Periodic Table does it belong and what is its valency? (iii) If 'X' burns in oxygen to form its oxide, what will be its nature - acidic, basic or neutral ? (iv) Write balanced chemical equation for the reaction when this oxide is dissolved in water. |
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Answer» Solution :(i) Electronic CONFIGURATION of X(19) - 2,8,8,1. (ii) Fourth PERIOD, Valency 1. (iii) Basic OXIDE `(X_(2)O)`. (IV) `X_(2)O+H_(2)Oto2XOH`. |
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