Problem 2
The wrong statement among the following is (1) Mcndclcev arranged the Elements in a tabular form according to increasing atomic weight. (2) Onc of the dcfects in Mcndclcev's periodic table is position of lanthanides. (3) Maximum number of groups in Bohr's periodic table is 18 . (4) Elements with similar chemical properties occur only within the same period.
Problem 3
Which of the following statement is false? (1) In modern periodic table the elements are arranged in increasing order of atomic number. (2) The number of periods in the long form periodic table is \(7 .\) (3) The long form periodic table is nothing but just a graphical representation of Paulis principle. (4) Elements of III period are called typical elements.
Problem 6
Which of the following statement is false? (1) The group in which all the elements do not have same number of valence electrons is zero. (2) Elements of II period elements are collectively called as bridge elements. (3) The cause of periodicity of properties is reoccurrence of similar outer electronic configuration. (4) The most reactive gaseous element in the second period is oxygen.
Problem 8
The statement that is not correct for the periodic classification of elements is (1) The properties of elements are the periodic functions of their outer electronic configurations. (2) Non-metallic elements arc lesser in number than metallic elements. (3) For transition elements the d-subshells are filled with electrons monotonically with increase in atomic number. (4) In the periodic table metallic elements appear in the right-hand columns.
Problem 9
Which of the following statement is wrong? (1) In the sixth period the orbitals being filled arc \(6 \mathrm{~s}\), \(4 \mathrm{f}, 5 \mathrm{~d}\), and \(6 \mathrm{p}\). (2) All the elements in a group in the periodic table have the same number of electrons in the outer most shell of their atoms. (3) Periodicity in the properties of elements when elements are arranged in increasing order of their atomic weights is that elements with similar nature repeat after certain fixed interval. (4) The last member in each period of the periodic table is an inert gas.
Problem 11
An element having the electronic configuration of its atom as \(\mathrm{ns}^{2} \mathrm{n} \mathrm{p}^{2}\) should have similar properties to those of (1) Sodium (2) Carbon (3) Magnesium (4) Oxygen
Problem 12
Which pair of clcments belong to the same group? (1) Elements with atomic number 17 and 38 (2) Elements with atomic number 20 and 40 (3) Elements with atomic number 17 and 53 (4) Elements with atomic number 11 and 53
Problem 13
Which pair has both members from the same period of pcriodic tablc? (1) \(\mathrm{Mg}, \mathrm{Ba}\) (2) \(\mathrm{Mg}, \mathrm{Na}\) (3) \(\mathrm{Mg}, \mathrm{Cu}\) (4) \(\mathrm{K}, \mathrm{Cl}\)
Problem 14
Each period in the periodic table starts with a s-subshell of the new shell and ends with filling of (1) Same subshell (2) p-subshell of the same shell (3) p-subshell of the next shell (4) d-subshell of the same shell
Problem 15
The clectronic configuration of two elements \(\Lambda\) and \(B\) are respectively \(1 s^{2} 2 s^{2} 2 p^{6}\) and \(1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6}\). Thereforc, their positions in the periodic table are (1) A after B (2) A before B (3) A above B (4) A below B
