Chemistry · Science General

Periodic Table and Elements

406 Questions

The periodic table and elements questions test knowledge of chemical properties, atomic structures, and periodic trends. Topics include alkali metals, transition elements, and ionisation potential. These concepts frequently appear in general science sections of competitive examinations.

Alkali metals propertiesTransition elementsLattice energyIonisation potentialAlkaline earth metals

Periodic Table and Elements Questions

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) anomalous properties of lithium group 1 elements: alkali metals properties of s block elements

In certain matters, lithium differs from other alkali metals, the main reason for this is:

  1. Small size of lithium atom and $Li^+$ ion
  2. Extremely high electro positivity of $Li$
  3. Greater hardness of $Li$
  4. Hydration of $Li^+$ ion
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The chemistry of lithium shows several differences from that of the rest of the group as the small lithium cation polarises anions and gives its compounds as the more covalent character.

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) anomalous properties of lithium group 1 elements: alkali metals properties of s block elements

Which of the following pairs shows diagonal relationship?

  1. $Na$ and $Mg$
  2. $Li$ and $Mg$
  3. $Li$ and $Na$
  4. $Al$ and $C$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A diagonal relationship is said to exist between certain pairs of diagonally adjacent elements in the second and third periods of the periodic table. Thus, $Li$ and $Mg$ are diagonally related.

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) anomalous properties of lithium group 1 elements: alkali metals properties of s block elements

$Li$ and $Mg$ resembles each other because

  1. both are s-block elements

  2. both are metals

  3. both have almost same periodic properties

  4. they have same electronic configuration
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Due to its small size, lithium differs from other alkali metals but resembles with Mg as its size and other periodic properties are closer to Mg. Its resemblance with Mg is known as diagonal relationship.

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) anomalous properties of lithium group 1 elements: alkali metals properties of s block elements

${Li} _{2}{SO} _{4}$ is not isomorphous with sodium sulphate, due to:

  1. small size of lithium

  2. high coordination number of lithium

  3. high ionization energy of lithium

  4. none of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Isomorphic compounds have same crystal structure at given temperature and conditions. While $LiSO _4$ and $Na _2SO _4$ are not isomorphous due to the exceptionally small size of Lithium (Li).

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) anomalous properties of lithium group 1 elements: alkali metals properties of s block elements

Which of the following does not show the anomalous behaviour of Lithium?

  1. Lithium reacts with nitrogen to form a nitride

  2. Lithium carbonate decomposes on heating
  3. Lithium nitrate gives $NO _2$ on heating

  4. Lithium is the strongest reducing agent
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Anomalous behavior of lithium is due to extremely small size of lithium. Its cation on account of small size and high nuclear charge, lithium exerts the greatest polarizing effect out of all alkali metals on the negative ion. Consequently, lithium ion possesses a remarkable tendency towards solvation and develops a covalent character in its compounds.

But lithium like other metals of the same group is a strong reducing agent. In fact, Lithium is the strongest reducing agent in aqueous solution.

Thus option D is correct.
Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) anomalous properties of lithium group 1 elements: alkali metals properties of s block elements

The properties of $Li$ are similar to those of $Mg$. This is because:

  1. both have nearly the same size.

  2. both has their charge to size ratio nearly the same.

  3. both have similar electronic configurations.

  4. both are found together in nature.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • The properties of lithium are similar to those of $Mg$ because they are having diagonal relationship.
  • The elements having diagonal relationship show similar properties and the reason is because the both of them will have similar electronegativity and polarising power i.e. charge per size ratio of both the elements are nearly the same.
Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) anomalous properties of lithium group 1 elements: alkali metals properties of s block elements

Choose the correct answer form the alternatives given.
Which of the following statements is not true about alkali metals ?

  1. All alkali metals from oxo salts such as carbonates, sulphates and nitrates.

  2. The basic character of oxides increases down the group.

  3. Carbonates and sulphates of lithium are stable and their stability decreases down the group.

  4. Solubility of carbonates and sulphates increases down the group.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Characteristics of Alkali Metals-
  • Found in column 1A of the periodic table.
  • Have one electron in their outermost layer of electrons.
  • Easily ionized.
  • Silvery, soft, and not dense.
  • Low melting points.
  • Incredibly reactive.
  • They form oxo salts such as carbonates, sulphates and nitrates.
  • The basic character of oxides increases down the group.
  • The acidic character of oxides decreases down the group.
  • Solubility of carbonates and sulphates increases down the group.
  • As we move down the alkali metal group, the electropositive character increases. This causes an increase in the stability of alkali carbonates. However, lithium carbonate is not so stable to heat. This is because lithium carbonate is covalent.
  • Hence option C is not correct about alkali metals.
Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) anomalous properties of lithium group 1 elements: alkali metals properties of s block elements

Choose the correct answer form the alternatives given.
Which of the following has lowest thermal stability?

  1. $Li _2CO _3$
  2. $Na _2CO _3$
  3. $K _2CO _3$
  4. $Rb _2CO _3$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Lithium carbonates are least thermal stable compound which decompose upon heating to give lithium oxide and carbon dioxide.
$ { Li } _{ 2 }C{ O } _{ 3 }\ \rightarrow {  Li } _{ 2 }O\ +\ C{ O } _{ 2 } $

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) anomalous properties of lithium group 1 elements: alkali metals properties of s block elements

The solubility of metal halides depends on their nature, lattice enthalpy and hydration enthalpy of the individual ions. Amongst fluorides of alkali metals, the lowest solubility of LiF in water is due to:

  1. ionic nature of lithium fluoride

  2. high lattice enthalpy

  3. high hydration enthalpy for lithium ion

  4. low ionisation enthalpy of lithium atom
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Lowest solubility of $LiF$ is due to high lattice enthalpy which is higher than hydration enthalpy. Hence, the dissociation of $Li-F$ bond becomes difficult.

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) anomalous properties of lithium group 1 elements: alkali metals properties of s block elements

$Li$ has an abnormal behaviour in its group, which is ____________.

  1. lithium carbonate decomposes into its oxide on heating unlike other elements.
  2. $LiCl$ is covalent in nature.
  3. $Li _3N$ is a stable compound.
  4. $LiCl$ is a good conductor of electricity in the molten state.
Reveal answer Fill a bubble to check yourself
A,B,C Correct answer
Explanation

(A). Lithium carbonate, being less stable, decomposes into its oxide on heating, whereas other group IA carbonates are stable and do not decompose.


${ Li } _{ 2 }C{ O } _{ 3 }\ \underrightarrow { \triangle  } \ { Li } _{ 2 }O+C{ O } _{ 2 }$

(B). Lithium halides, except fluoride, are covalent due to fajan's rule.

(C) Lithium is the only 1A metal that can combine with inert nitrogen in air to form lithium nitride.

(D) Lithium chloride , like other alkali metals compounds , is a good conductor of electricity in molten state. 

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) anomalous properties of lithium group 1 elements: alkali metals properties of s block elements

Which of the following statement(s) is/are true?

  1. Both $LiCl$ and $MgCl _{2}$ are deliquescent.

  2. Lithium is least reactive but the strongest reducing agent amongst all the alkali metals.

  3. Liquid sodium metal is used as a coolant in fast breeder nuclear reactors.

  4. Lithium iodide is the most ionic in nature among all alkali metal halides.
Reveal answer Fill a bubble to check yourself
A,B,C Correct answer
Explanation

(A) $Li^{+}$ and $Mg^{2+}$ have higher polarising power and thus attract more number of water molecules.
(B) $Li$ is least reactive because of its highest ionisation energy on account of smaller size.
(C) It is one of the uses of liquid sodium as it has low melting point.
(D) $LiI$ is the most covalent due to smaller cation and bigger anion (according to Fajan's rule).

Multiple choice chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

Metallic bonding describes an array of positively charged metal cations surrounded by a sea of electrons that makes up a class of substances known as which of the following?

  1. Alloys

  2. Allotropes

  3. Isomers

  4. Ions
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Answ: (A) Alloys

- We know that alloys is mixture of two or more metals. Which is held by metallic bond.
eg : brass which is made from copper and zinc.

Multiple choice chemistry p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

Which requires the highest energy for excitation?

  1. F

  2. Cl

  3. Br

  4. I
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fluorine has a small size thus it has a high nuclear charge and its electrons are strongly attracted towards the nucleus. Thus it requires high energy for excitation. Among halogen atoms, fluorine requires the highest energy for excitation.