Important MCQs on Classification of Elements and Periodicity in Properties

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Classification of Elements and Periodicity in Properties deals with the concept of elements and their periodic classification in the modern periodic table as per the periodic law. The modern periodic table divides the elements into seven horizontal rows (periods) and eighteen vertical columns according to the sequence of their atomic numbers (groups). Atomic number increases in a pattern in a group but is consecutive in a period. The valence shell electrical arrangement and chemical characteristics of elements belonging to the same group are comparable. However, the valencies of the elements belonging to the same period are different because of the progressively increasing number of electrons from left to right.

Based on the electrical structures of all the elements, the periodic table can distinguish between four different sorts of elements. These are elements of the s-block, p-block, d-block, and f-block. Atomic sizes, ionization enthalpies, electron gain enthalpies, electronegativity, and valence electrons all exhibit periodic trends. The two ends of a period are where chemical reactivity is strongest, and the middle is where it is lowest. Due to the easiness of electron loss, periods on the left extreme are more reactive (or low ionization enthalpy).

Here are some important MCQs on Classification of Elements and Periodicity in Properties for the students to help them test their knowledge on the given topic.

Ques 1. Examining periodic trends in the ________ is done using the periodic classification of elements.

physical properties of elements
recurring patterns in the chemical characteristics of components
None of the above
both (a) and (b)

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Ans. (D) Both (A) and (B)

Explanation: The electronic arrangement of atoms, which is used to study the physical and chemical properties of the elements, has a logical effect on the periodic classification of elements.

Ques 2. The ionization enthalpies of the elements decline from top to bottom in a group of the periodic table due to ________.

Increased densities
a decline in the reactivities of chemicals
the expansion of the atomic size
Reduced electronegativities are

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Ans. (C) the expansion of the atomic size

Explanation: The atomic size increases down the periodic table. Due to a rise in atomic size, a set of elements in the periodic table have ionization enthalpies that drop from top to bottom.

Ques 3. An element's electrical configuration is 1s², 2s², 2p⁶, 3s²3p³. What is the atomic number of the element in the periodic table that is immediately below the one above?

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Ans. (B) 33

Explanation: The sum of all the electrons in the given electronic configuration will determine the atomic number. The element that is present just below the given element will have an outermost electronic configuration as 4s²4p³, hence, its full electronic configuration will be 1s²,2s²2p⁶,3s²3p⁶,4s², 3d¹⁰,4p². Thus, its atomic number is 33.

Ques 4. Despite being in separate groups, lithium and magnesium have remarkably similar chemical makeup. It does so for several reasons, including the following:

both can be found together in nature
both have almost the same size
both have similar electronic configurations
and the ratio of their charge to size (i.e. charge density) is almost the same.

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Ans. (D) and the ratio of their charge to size (i.e. charge density) is almost the same.

Explanation: Their charge density, or the ratio of charge to size, is very similar. Even though they are grouped differently due to a diagonal relationship, lithium and magnesium have remarkably comparable chemical properties.

Read More: Ionization Energy Formula

Ques 5. What electronic arrangement of an atom has the lowest ionization enthalpy among the following?

1s² 2s² 2p³
1s² 2s² 2p⁶3s¹
1s² 2s² 2p⁶
1s² 2s² 2p⁵

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Ans. (B) 1s²2s²2p⁶3s¹

Explanation: The amount of energy needed to remove one electron from an isolated gaseous atom's outermost orbit is known as the ionization enthalpy. The ionization enthalpy is lowest for the electronic structure 1s²2s²2p⁶3s¹.

Ques 6. The atomic radii of the elements O, S, Se, and As are rising in size in the following order:

As < S < O < Se
Se < S < As < O
O < S < As < Se
O < S < Se < As

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Ans. (D) O < S < Se < As

Explanation: Atomic radii increase as you move down in a group as new shells are added one at a time, which is why O<S<Se. Additionally, As is in group 15 and has one fewer electron in its p orbital than group 16 elements, giving it a bigger atomic radius. Thus, O<S<Se<As.

Do Check Out:

Related Links
First 20 Elements of Periodic Table	Electronegativity Chart of Elements	Mendeleev's Periodic Table
Difference Between Atomic Mass and Atomic Number	Atomic Number and Mass Number	Nomenclature of Elements with Atomic Numbers Above 100
Position of Hydrogen in the Periodic Table	Periodicity of Valence or Oxidation State of Elements	Electron Emission

Ques 7. An element with the atomic number 15 has the following group number, valence electron count, and valency values, in that order:

16, 5 and 2
15, 5 and 3
16, 6 and 3
15, 6, and 2

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Ans. (B) 15, 5, and 3

Explanation: Atomic number 15 (Z) belongs to P, this can be written as [Ne] 3s²3p³

Phosphorus is in group 15 of elements. In the ground state, the valence electron count for phosphorus is 5 and the valency is 3, from 3s²3p³.

Ques 8. The period in the current periodic table denotes the value of the following quantities:

Atomic Number
Atomic Mass
Principal Quantum Number
Azimuthal Quantum Number

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Ans. (C) Principal Quantum Number

Explanation: The chemical elements are arranged in a periodic table according to their atomic number (the number of protons in the nucleus), electron configurations, and characteristic chemical properties. A period in the Modern Periodic Table is indicated by the value of the primary quantum number (n) for the outermost shell or the valence shell.

Ques 9. The cation's ionic radius is always __________

a smaller radius than the radius of its atom
the atomic radius plus
equal to the atomic radius
Impossible to anticipate

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Ans. (A) a smaller radius than the radius of its atom

Explanation: The cation's ionic radius is always less than its atomic radius. The loss of electrons produces cations. Ionic radius decreases as a result of the rise in effective nuclear charge.

Ques 10: Elements of which of the following parts exhibit the property of decreasing atomic size with increasing atomic number.

d−block
f−block
Radioactive series
High atomic masses

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Ans. (B) f-block

Explanation: A trait of elements in the f-block is the decrease in atomic size with the increase in atomic number. Both lanthanoid and actinoid contractions refer to it. This is brought on by the f subshell's electrons' inadequate shielding.

Ques 11: Sort S, O, and Se according to their increasing electron affinities

Se < S < O
O < Se < S
S < O < Se
S < Se < O

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Ans. (B) O < Se < S

Explanation: A group's electron affinity declines as its atomic number rises. Se, O, and S are all group 16 elements. Thus, the expected order of their increasing electron affinities would be O>S>Se. However, this is not the observed case as the oxygen atom is extremely small. So, oxygen cannot hold a negative charge in such a small space. Therefore, the electron affinity of oxygen is the lowest in the group.

Ques 12. Which order best depicts the oxides' progressively less acidic nature?

Li₂O > BeO > B₂O₃ > CO₂ > N₂O₃
N₂O₃ > CO₂ > B₂O₃ > BeO > Li₂O
CO₂ > N₂O₃ > B₂O₃ > BeO > Li₂O
B₂O₃ > CO₂ > N₂O₃ > Li₂O > BeO

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Ans. (B) N₂O₃ > CO₂ > B₂O3₂> BeO > Li₂O

Explanation: The typical oxides of elements become more acidic as you move from left to right in a period as their electronegativity rises.

Ques 13. Which of the following oxides has the characteristics of an amphoteric?

SnO₂
CO₂
SiO₂
CaO

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Ans. (a) SnO₂

Explanation: SiO₂ is slightly acidic, CaO is basic, and CO₂ is acidic. SnO₂ is amorphous.

Read More: Classification of Oxides

Ques 14: Elements that are considered to be representative elements are those that belong to

p and d–Block
s and d–Block
s and p–Block
s and f–Block

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Ans. (C) s and p–Block

Explanation: The term "representative elements" refers to substances with complete inner shells but incomplete outer shells, i.e., substances with fewer than 8 electrons in the outermost shell. Except for inert gas, the s and p block elements are referred to as representative elements.

Ques 15. The element next to F on Pauling's electronegativity scale is

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Ans. (C) O

Explanation: The ability of an atom in a molecule to draw electrons toward it is known as electronegativity, according to Pauling. When we examine the periodic table's trend, we can observe that while electronegativity increases between periods, it drops as we move down the groups. Pauling estimated the differences in electronegativity between the atoms in a covalent bond based on the bond energies and assigned the most electronegative element, fluorine, a value of 4, and other elements were calculated concerning that value. So, on Pauling's scale, oxygen is the element following fluorine.

Also check:

Class 11 & 12 PCMB Study Guides
Chemistry MCQs	NCERT Solutions for Class 12 Chemistry	Mendeleev's Periodic Table
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Comparison Topics in Physics	Class 12 Physics Book PDF	Physics Practicals
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Class 12 Physics Syllabus	Class 12 Physics Notes	Class 12 Biology Notes
Physics Study Notes	NCERT Solutions for Class 12 Maths	Class 12 Chemistry Practicals
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Class 12 PCMB Notes	NCERT Class 12 Biology Book	Biology MCQs
NCERT Class 12 Textbooks	NCERT Solutions for Class 11 Maths	Important Maths Formulas
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Comparison Topics in Maths	NCERT Solutions for Class 11 Chemistry	Important Named Reactions
Important Chemical Reactions	NCERT Class 12 Maths Book	NCERT Solutions for Class 12 Physics

Important MCQs on Classification of Elements and Periodicity in Properties

Here are some important MCQs on Classification of Elements and Periodicity in Properties for the students to help them test their knowledge on the given topic.

CBSE CLASS XII Related Questions

1.
Write equations of the following reactions:
(i)Friedel-Crafts reaction–alkylation of anisole.
(ii)Nitration of anisole.
(iii)Bromination of anisole in ethanoic acid medium.
(iv)Friedel-Craft’s acetylation of anisole.

2.
The rate constant for the decomposition of hydrocarbons is 2.418 x 10^-5 s^-1 at 546 K. If the energy of activation is 179.9 kJ/mol, what will be the value of pre-exponential factor.

3.
Write down the electronic configuration of:
(i) Cr³⁺ (iii) Cu⁺ (v) Co²⁺ (vii) Mn²⁺
(ii) Pm³⁺ (iv) Ce⁴⁺ (vi) Lu²⁺ (viii) Th⁴⁺

6.
In the button cells widely used in watches and other devices the following reaction takes place:
Zn(s) + Ag₂O(s) + H₂O(l) \(\rightarrow\) Zn²⁺_(aq) + 2Ag(s) + 2OH^- (aq)
Determine \(\triangle _rG^\ominus\) and \(E^\ominus\) for the reaction.

Similar Chemistry Concepts

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Important MCQs on Classification of Elements and Periodicity in Properties

Here are some important MCQs on Classification of Elements and Periodicity in Properties for the students to help them test their knowledge on the given topic.

CBSE CLASS XII Related Questions

1. Write equations of the following reactions: (i)Friedel-Crafts reaction–alkylation of anisole.(ii)Nitration of anisole.(iii)Bromination of anisole in ethanoic acid medium.(iv)Friedel-Craft’s acetylation of anisole.

2. The rate constant for the decomposition of hydrocarbons is 2.418 x 10-5 s-1 at 546 K. If the energy of activation is 179.9 kJ/mol, what will be the value of pre-exponential factor.

3. Write down the electronic configuration of:(i) Cr3+ (iii) Cu+ (v) Co2+ (vii) Mn2+ (ii) Pm3+ (iv) Ce4+ (vi) Lu2+ (viii) Th4+

6. In the button cells widely used in watches and other devices the following reaction takes place:Zn(s) + Ag2O(s) + H2O(l) \(\rightarrow\) Zn2+(aq) + 2Ag(s) + 2OH- (aq) Determine \(\triangle _rG^\ominus\) and \(E^\ominus\) for the reaction.

Similar Chemistry Concepts

Comments

SUBSCRIBE TO OUR NEWS LETTER

1.
Write equations of the following reactions:
(i)Friedel-Crafts reaction–alkylation of anisole.
(ii)Nitration of anisole.
(iii)Bromination of anisole in ethanoic acid medium.
(iv)Friedel-Craft’s acetylation of anisole.

2.
The rate constant for the decomposition of hydrocarbons is 2.418 x 10^-5 s^-1 at 546 K. If the energy of activation is 179.9 kJ/mol, what will be the value of pre-exponential factor.

3.
Write down the electronic configuration of:
(i) Cr³⁺ (iii) Cu⁺ (v) Co²⁺ (vii) Mn²⁺
(ii) Pm³⁺ (iv) Ce⁴⁺ (vi) Lu²⁺ (viii) Th⁴⁺

6.
In the button cells widely used in watches and other devices the following reaction takes place:
Zn(s) + Ag₂O(s) + H₂O(l) \(\rightarrow\) Zn²⁺_(aq) + 2Ag(s) + 2OH^- (aq)
Determine \(\triangle _rG^\ominus\) and \(E^\ominus\) for the reaction.