MCQ of Classification of Elements and Periodicity in Properties |Chapter 3 |

MCQ of Classification of Elements and Periodicity in Properties, Chapter 3, Class 11. Chemistry

 

Question 1: According to the law of triads,

  1. The properties of the middle element were in between those of the other two members
  2. Three elements arranged according to increasing weight have similar properties
  3. The elements can be grouped in the groups of six elements
  4. Every third element resembles the first element in periodic table

Answer: A (The properties of the middle element were in between those of the other two members)

Question 2: The first periodic law stated by Mendeleev was

  1. There is no correlation in the properties and atomic weights of the elements
  2. The properties of the elements are a periodic function of their atomic numbers
  3. The properties of the elements are a periodic function of their atomic weights
  4. The properties of the elements are a periodic function of an empirical formula

Answer: C (The properties of the elements are a periodic function of their atomic weights)

Question 3: Which of the following is not a property of Mendeleev’s periodic table?

  1. It helped in correcting the atomic masses of some of the elements
  2. He predicted the properties of some and discovered elements and left gaps for them
  3. He framed the periodic table with vertical and horizontal columns and gave shape to it
  4. He gave separate places to isotopes in his periodic table

Answer: D ( He gave separate places to isotopes in his periodic table )

Question 4: The period to which an element belongs to in the long form of periodic table represents

  1. Atomic mass
  2. Atomic number
  3. Principal quantum number
  4. Azimuthal quantum number

Answer: C (Principal quantum number)

Question 5: Elements belonging to the same group of periodic table have

  1. Same number of energy levels
  2. Same number of valence electrons
  3. Same number of electrons
  4. Same ionization enthalpy

Answer: B (Same number of valence electrons)

Question 6: Anything that influences the valence electrons will affect the chemistry of the element. Which one of the following factors does not affect the valence shell?

  1. Principal quantum number (n)
  2. Nuclear charge (Z)
  3. Nuclear mass
  4. Number of core electrons

Answer: C (Nuclear mass)

Question 7: Which of the following statements is correct?

  1. Elements of 3d and 4d series are kept separately in periodic table
  2. Elements of 4f and 5f series are kept separately in periodic table
  3. Elements of 5p and 6p series are kept separately in periodic table
  4. All statements are correct

Answer: B (Elements of 4f and 5f series are kept separately in periodic table)

Question 8: Which statement is false?

  1. Elements of group 16 are called chalcogens
  2. Elements of group 15 are called metalloids
  3. Elements of group 1 are alkali metals
  4. Elements of group 14 are neither electronegative nor strongly electropositive

Answer: B (Elements of group 15 are called metalloids)

Question 9: There are two rows of inner transition elements in the periodic table each containing 14 elements. The reason for this may be

  1. f orbital has seven values of magnetic quantum number hence total electrons are 14.
  2. In the periodic table there is space to accommodate 14 electrons only
  3. Only 28 inner transition elements have been discovered till date
  4. 28 is the maximum number of elements that any block can accommodate

Answer: A (f orbital has seven values of magnetic quantum number hence total electrons are 14)

Question 10: Which of the following statements is correct on the basis of the periodic table ?

  1. The most electronegative element in the periodic table is fluorine.
  2. Scandium is the first transition element and belongs to fourth period
  3. Along a period halogens have maximum negative electron gain enthalpy
  4. All of these

Answer: D (All of these)

You may also read MCQ of Basic Concepts of Chemistry, MCQ of Structure of AtomMCQ of Chemical Bonding and Molecular Structure, MCQ of States of Matter, MCQ of Redox Reactions, MCQ of Hydrogen, MCQ of Organic Chemistry; Some Basic Principles and Techniques for better understanding of the chapters.

Question 11: Which of the following statements regarding the variation of atomic radii in the periodic table is not true?

  1. In a group there is continuous increase in size with increasing atomic number
  2. In 4f series there is continuous decrease in size with increase in atomic number
  3. The size of inert gases is larger than halogens
  4. In 3rd period the size of atoms increases with increase in atomic number

Answer: D (In 3rd period the size of atoms increases with increase in atomic number)

Question 12: Ionic radius in a group while moving down

  1. Remains same from top to bottom
  2. Decreases from top to bottom
  3. Increases from top to bottom
  4. First increases and then decreases

Answer: C (Increases from top to bottom)

Question 13: K+ and Cl¯ ions are isoelectronic. Which of the statements is not correct?

  1. Both K+ and Cl¯ ions contain 18 electrons
  2. Both K+ and Cl¯ ions have same configuration
  3. K+ ion is bigger than Cl¯ ion in ionic size
  4. Cl¯ ion is bigger than K+ ion in ionic size

Answer: C (K+ ion is bigger than Cl- ion in ionic size)

Question 14: Ionisation enthalpy of nitrogen is more than oxygen because of

  1. Extra stability of half filled orbitals
  2. More number of energy levels
  3. Less number of valence electrons
  4. Smaller size

Answer: A (Extra stability of half filled orbitals)

Question 15: Beryllium has higher ionization enthalpy than boron. This can be explained as

  1. Beryllium has higher size than boron hence its ionization enthalpy is higher
  2. Penetration of 2p- electrons to the nucleus is more than the 2s-electrons
  3. It is easier to remove electron from 2p-orbital as compared to 2s-orbital due to penetration of s-electrons.
  4. Ionisation energy increases in a period

Answer: C (It is easier to remove electron from 2p-orbital as compared to 2s-orbital due to penetration of s-electrons)

Question 16: Which of the following will have lowest electron affinity?

  1. Nitrogen
  2. Oxygen
  3. Argon
  4. Boron

Answer: C (Argon)

Question 17: Which of the following statements is not correct about the electron gain enthalpy?

  1. In general the electron gain enthalpy become less negative in going from top to bottom in a group
  2. The electron gain enthalpy becomes less negative in a period from left to right
  3. The elements having stable configuration like noble gases have large positive electron gain enthalpies
  4. Halogen have highest negative electron gain enthalpy

Answer: B (The electron gain enthalpy becomes less negative in a period from left to right)

Question 18: Why is the gain enthalpy of O or F less than that of S or Cl?

  1. O and F are more electronegative than S and Cl.
  2. When an electron is added to O or F, it goes to a smaller (n=2) level and suffers more repulsion than the electrons in S or Cl in larger (n=3) level
  3. Adding an electron to 3p orbital leads to more repulsion than 2p-orbital
  4. Electron gain enthalpy depend upon the electron affinity of the atom

Answer: B (When an electron is added to O or F, it goes to a smaller (n=2) level and suffers more repulsion than the electrons in S or Cl in larger (n=3) level)

Question 19: Which of the following statements regarding an anion is not true?

  1. The gain of an electron leads to the formation of an anion
  2. The radius of the anion is larger than the atomic radius of its parent atom
  3. The effective nuclear charge increases when an anion is formed
  4. Electron cloud expands due to increased repulsion among the electrons

Answer: C (The effective nuclear charge increases when an anion is formed)

Question 20: Given below are the names of few elements based on their position in the periodic table. Identify the element which is not correctly placed.

  1. An element which tends to lose three electrons – Aluminium
  2. An element which tends to gain two electrons – Iodine
  3. An element with valency four – Silicon
  4. A transuranium element – Plutonium

Answer: B (An element which tends to gain two electrons – Iodine)

Question 21: Why do noble gases have positive electron gain enthalpy?

  1. It is difficult to add an electron due to small size
  2. It is difficult to add an electron due to higher electronegativity
  3. It is difficult to add an electron due to stable configuration
  4. It is difficult to add an electron due to high electron affinity

Answer: C (It is difficult to add an electron due to stable configuration)

Question 22: As move from left to right the electronegativity increases. An atom which is highly electronegative has

  1. Large size
  2. Low electron affinity
  3. High ionization enthalpy
  4. Low chemical reactivity

Answer: C (High ionization enthalpy)

Question 23: Which of the following is not a periodic property for the elements ?

  1. Electronegativity
  2. Atomic size
  3. Occurrence in nature
  4. Ionization energy

Answer: C (Occurrence in nature)

Question 24: Choose the incorrect statement

  1. Chemical reactivity tends to be  in group 1 metals, lower in elements in middle and increases to maximum in the group 17
  2. Halogens have very high negative electron gain enthalpy
  3. Noble gases have large positive electron gain enthalpy
  4. Decrease in electronegativities across a period is accompanied by an increase in non metallic properties

Answer: D (Decrease in electronegativities across a period is accompanied by an increase in non metallic properties )

Question 25: In the periodic table, the maximum chemical reactivity is at the extreme left (alkali metals) and extreme right (halogens). Which properties of these two groups are responsible for this?

  1. Least ionization enthalpy on the left and highest negative electron gain enthalpy on the right
  2. Non metallic character on the left and the metallic character on the right
  3. High atomic radii on the left and smaller atomic radii on the right
  4. Highest electronegativity on the left and least electronegativity on the right

Answer: A (Least ionization enthalpy on the left and highest negative electron gain enthalpy on the right)

Question 26: The oxidation state of an element in a particular compound can be defined as

  1. The charge acquired by its atom on the basis of electronegative consideration from other atom in the molecule
  2. The residual charge acquired by its atom after removing electronegative atoms from the molecule
  3. The valency of the most electronegative atom present in the molecule
  4. Total number of electrons accepted by an atom to form a molecule

Answer: A (The charge acquired by its atom on the basis of electronegative consideration from other atom in the molecule)

Question 27: Electropositive or metallic character

  1. Increases along a period
  2. Decreases down a group
  3. Decrease along a period and increases down a group
  4. Of an element is reflected in its tendency to form covalent compounds

Answer: C (Decrease along a period and increases down a group )

Question 28: The main reason for showing anomalous properties of the first member of a group in s or p-block is

  1. They have maximum chemical reactivity
  2. They have maximum electronegativity and different configuration
  3. Small size, large charge/ radius ratio
  4. Tendency to form multiple bonds

Answer: C (Small size, large charge/ radius ratio)

Question 29: What is the common property of the oxides CO, NO and N2O?

  1. All are acidic oxides
  2. All are basic oxides
  3. All are neutral oxides
  4. All are amphoteric oxides

Answer: C (All are neutral oxides)

Question 30: The first ionization enthalpies of Na, Mg , Al and Si are in the order

  1. Na < Mg > Al < Si
  2. Na > Mg > Al > Si
  3. Na < Mg < Al < Si
  4. Na > Mg > Al < Si

Answer: A (Na < Mg > Al < Si)

Question 31: The  statement is not correct for periodic classification of element is

  1. The properties of elements are periodic function of their atomic numbers
  2. Non metallic elements are less in number then metallic elements
  3. For transition elements, the 3d orbitals are filled with electrons after 3p orbitals and before 4s orbitals
  4. The first ionization enthalpies of elements generally increases with increase in atomic number as we go along a period

Answer: C (For transition elements, the 3d orbitals are filled with electrons after 3p orbitals and before 4s orbitals)

Question 32: The period number in the long form of the periodic table is equal to

  1. Magnetic quantum number for any element of the period
  2. Atomic number of any element of the period
  3. Maximum principal quantum number of any element of the period
  4. Maximum azimuthal quantum number of any element of the period

Answer: C (Maximum principal quantum number of any element of the period) 

Question 33: Which of the following elements have highest electron affinity?

  1. Chlorine
  2. Nitrogen
  3. Phosphorous
  4. Fluorine

Answer: A (Chlorine)

Question 34: Identify the wrong statement in the following.

  1. Amongst isoelectronic species, smaller the positive charge on the cation, smaller is the ionic radius
  2. Amongst isoelectronic species, greater the negative charge on the anion, larger is the ionic radius
  3. Atomic radius of the element increases as we move down the first group of the periodic table
  4. Atomic radius of the elements decreases as we move across from left to right in the second period of the periodic table

Answer: A (Amongst isoelectronic species, smaller the positive charge on the cation, smaller is the ionic radius)

Question 35: First ionization enthalpy of group 2 elements are greater than that for group 1 and group 13 elements due to

  1. Stable electronic configuration of group 2 elements
  2. Bigger atomic size of group 2 elements
  3. Smaller effective nuclear charge of group 2 elements
  4. All of these

Answer: A (Stable electronic configuration of group 2 elements)

Question 36: In general the properties the decrease and increase down a group in the periodic table respectively are

  1. Atomic radius and electronegativity
  2. Electronegativity and electron gain enthalpy
  3. Electronegativity and atomic radius
  4. Electron gain enthalpy and electronegativity

Answer: C (Electronegativity and atomic radius)

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