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

Which of the following statements is/are incorrect? A. The second ionisation potential of oxygen is lower than nitrogen. B. The degree of hydration of a cation increases with decrease in ionic size. C. Metals possess high electronegativity.

  1. Only A

  2. Only B

  3. Only C

  4. Only A and B

  5. Only A and C
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Wrong statement: The second ionisation potential of oxygen is lower than nitrogen.

The second ionisation potential of oxygen is higher than nitrogen.

Wrong statement: Metals possess high electronegativity.

Metals possess low electronegativity.

Multiple choice

Identify the incorrect statement(s) for boron.

P. Kernite is a mineral of boron. Q. 10B is more abundant isotope than11B. R. Boron has lower second ionization enthalpy than aluminium.

  1. P only

  2. Q only

  3. R only

  4. P and Q

  5. Q and R
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

P. Kernite (Na2B4O7.4H2O) is the mineral of boron. Q. There are two isotopic forms of boron 10B (19%) and 11B (81%). R. Boron (2427 KJ/mol) has higher second Ionization enthalpy than aluminium (1816 KJ/mol).

Multiple choice

Which of the following group 13 elements has the highest melting point?

  1. B

  2. Al

  3. Ga

  4. In

  5. Tl
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Boron (B) is metalloid and has melting point of 2076oC. Al has melting point 660oC, Ga has melting point of 29.8oC, In has the melting point of 156oC and Tl has the melting point of 303oC.  Hence, boron has the highest melting point among the given elements.

Multiple choice

Which of the following statements is incorrect?

  1. Iron is the most abundant transition metal.

  2. Copper is the best reducing agent among 3d series transition elements.

  3. Zr and Hf have the same atomic size.

  4. Ti4+ is colourless.

  5. Osmium is the densest transition element.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

All the elements of 3d series are good reducing agents except copper.

Multiple choice

Which of the following statements is incorrect?

  1. Larger number of oxidation states is exhibited by actinides than those by lanthanides.

  2. 4f and 5f orbitals are equally shielded.

  3. There is a decrease in the radii of the atoms or ions as one proceeds from La to Lu.

  4. Lanthanum has partially filled d orbitals and no other partially filled orbital.

  5. Lutetium is the densest lanthanide.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

4f orbital electrons are shielded more than 5f orbital electrons.

Multiple choice

Which of the following statements is correct?

  1. Lanthanum has smaller atomic radius than lutetium.

  2. Fluorides of lanthanides are water soluble.

  3. La3+ ions will exhibit colour in aqueous solutions.

  4. Lu3+ is diamagnetic.

  5. La(OH)3 is less basic than Lu(OH)3.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Lu3+ (64e-) = [Xe]4f14 Due to lack of unpaired electrons, Lu3+ ions are diamagnetic.

Multiple choice

Which of the following alkaline earth metals do not give characteristic flame colouration? P. Beryllium Q. Magnesium R. Calcium S. Strontium

  1. Only P

  2. P and Q

  3. P and R

  4. Q and S

  5. Only S
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Beryllium and magnesium atoms are comparatively smaller in comparison to other alkaline earth metals and their ionisation enthalpies are very high. Hence, the energy of the flame is not sufficient to excite their electrons to higher energy levels. Therefore, Be and Mg do not give any colour in Bunsen flame.

Multiple choice

Identify the incorrect statements. P. Alkaline earth metals have stronger metallic bonding than the corresponding alkali metals. Q. Alkaline earth metals have higher densities than corresponding alkali metals. R. Melting points in alkaline earth metals are lower than for the corresponding alkali metals. S. Alkaline earth metal carbonates have higher thermal stability than corresponding alkali metal carbonates.

  1. P and Q

  2. P and S

  3. Q and R

  4. Q and S

  5. R and S
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Melting points in alkaline earth metals are higher than for the corresponding alkali metals because the alkali metal neighbours. Alkaline-earth metals contribute two electrons per atom to the mobile electron cloud whereas alkali metals contribute only one electron per atom. The greater number of electrons and the smaller ionic size of the alkaline earth metals help to increase the density of the electron cloud and thus increase the attractive forces between the mobile electrons and the cationic lattice. Alkaline earth metal ions are much smaller in size than corresponding alkali metal ions and carry a higher charge. Thus, their polarizing power is greater. Electron cloud of carbonate anions are more easily distorted by alkaline earth metal ions than by alkali metal ions. Therefore, alkaline earth metal carbonates are less stable to heat and decompose to form metal oxide and carbon dioxide.

Multiple choice

Which of the following statements are FALSE regarding alkali metals?

  1. All alkali metals dissolve in liquid ammonia giving deep blue solutions.
  2. All alkali metals exhibit photoelectric effect.
  3. Reducing character of alkali metals in the gaseous state increases down the group.
  4. Lithium is most reactive but the weakest reducing agent among all the alkali metals.

  1. 1 and 2

  2. 1 and 3

  3. 2 and 3

  4. 2 and 4

  5. 3 and 4
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Alkali metals (except Li) exhibits photoelectric effect. The ionization enthalpy of lithium is quite high. The photons of light are not in a position to eject electrons from the surface of lithium metal. Therefore, photoelectric effect is not observed in lithium. Lithium is least reactive but the strongest reducing agent among all the alkali metals.

Multiple choice

For which following properties Li has higher value than Na? P. Hydration enthalpy Q. Thermal stability of hydride R. Stability of carbonate S. Basic character of hydroxide

  1. P and Q

  2. P and R

  3. P and S

  4. Q and R

  5. R and S
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The hydration enthalpies of alkali metal ions decrease with increase in ionic sizes. The correct order of hydration enthalpies of alkali metal ions is Li+ > Na+ > K+ > Rb+ > Cs+. The thermal stability of alkali metal hydrides decreases from LiH to CsH.

Multiple choice

Which of the following statements are FALSE regarding group 15 elements?

  1. The first ionization energies of the group 15 elements are higher than the corresponding members of the group 14 elements.
  2. The electronegativity values of elements of group 15 are lower than the corresponding elements of group 14.
  3. All elements of group 15 show allotropy.

  1. Only 1

  2. 1 and 2

  3. 1 and 3

  4. 2 and 3

  5. All are correct statements
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The electronegativity values of elements of group 15 are higher than the corresponding elements of group 14 because they have smaller size and greater nuclear charge of atoms. Except nitrogen and bismuth, all other elements of group 15 show allotropy. For example,  Phosphorus exists as white, black or red phosphorus.  Arsenic exists as yellow or grey arsenic.  Antimony exists as yellow or silvery grey antimony.

Multiple choice

Which of the following statements are FALSE? P. Sulphates and hydroxides of alkali metals are more soluble than those of alkali metals. Q. Solubility of alkaline earth metal sulphates increases down the group. R. Solubility of alkaline earth metal hydroxides decreases down the group. S. Alkaline earth metal ions have greater hydration enthalpies than alkali metal ions.

  1. P and Q

  2. P and R

  3. Q and R

  4. Q and S

  5. R and S
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

For the sulphates of alkaline earth metals, the cations are much smaller than the anions. On moving down the group, the change in size of the cations does not cause a significant change in ∆Hlattice, but ∆Hhydration becomes less negative. As a result, ∆Hsolution becomes less negative and the solubility of alkaline earth metal sulphates decreases down the group. For the hydroxides of alkaline earth metals, the size of the anions and cations are of the same order of magnitude. On moving down the group, less energy is required to break the lattice as the size of cations increases, but the change in ∆Hhydration is comparatively small. Consequently, the ∆Hsolution becomes more negative and the solubility of alkaline earth metal hydroxides increases down the group.