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 p- block elements-ii group 17 elements - general properties group 17 elements group 17 elements - properties

Which of the following have large electronegativity values?

  1. Alkali metals

  2. Alkaline Earth metals

  3. Metalloids

  4. Halogens

  5. Rare earth metals
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Electronegativity is a chemical property that describes the tendency of the atom to attract electrons towards itself.

Halogens have 7 electrons in their valence shell.
They need only 1 electron to complete their octet.
Hence, halogens are highly electronegative.

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

Among the following which has higher electron affinity value ?

  1. Fluorine

  2. Chlorine

  3. Bromine

  4. Iodine
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Electron Affinity: decreases down the group. Since the atomic size increases down the group, electron affinity generally decreases$ ( I < Br < F < Cl)$. An electron will not be as attracted to the nucleus, resulting in a low electron affinity. However, fluorine has a lower electron affinity than chlorine.

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

Which of the following has most ionisation enthalpy?

  1. $F$
  2. $Cl$
  3. $Br$
  4. $I$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

As the atomic size of the Florine is less it has more nuclear charge. So it requires more energy to remove the electron from its outer most orbit. So Florine has high ionization enthalpy and as we move down the group size increases nuclear charge decreases hence Ionization potential.

Hence option A is correect.

Multiple choice chemistry reactivity series and electrochemistry reactivity series and displacement reactions chemical properties of metals chemical properties of metals and non metals

An element is oxidized by fluorine but not by chlorine, could this element is oxidized?

  1. Sodium

  2. Sulphur

  3. Oxygen

  4. Aluminium
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Oxygen is the second most electronegative element in the periodic table and has electronegative value 3.5. So, it creates polarity that strongly attract the electron towards itself.

Multiple choice chemistry reactivity series and electrochemistry reactivity series and displacement reactions chemical properties of metals chemical properties of metals and non metals

Metals which lose electrons easily are said to be:

  1. less reactive than hydrogen

  2. more reactive than hydrogen

  3. have same reactivity as that of hydrogen

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

Metals which lose electrons less readily than hydrogen are said to be less reactive than hydrogen. All metals placed below hydrogen in the reactivity series lose electrons less readily than metals placed above hydrogen.

Multiple choice chemistry reactivity series and electrochemistry reactivity series and displacement reactions chemical properties of metals chemical properties of metals and non metals

The following elements are listed in order of decreasing reactivity as they appear in the electrochemical series.
      $\displaystyle Na, Ca, Mg, Zn, Fe, H, Cu, Hg, Ag, Au$

The element that is the best reducing agent is :

  1. $\displaystyle Na$
  2. $\displaystyle Au$
  3. $\displaystyle H$
  4. $\displaystyle Fe$
  5. $\displaystyle Cu$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Sodium lies above in the reactivity series. Therefore, it is the best reducing agents. It is a metal and therefore can lose electron so it can oxidize itself and can reduce others easily.

Multiple choice chemistry p- block elements-ii group 16 elements - general properties group 16 elements - trends in chemical properties group 16 elements

The properties like ionization potential, electronegativity, electron affinity and power of the catenation of the member in a group depend on many factors. For example, the smaller the size of the atom greater will be the ionization potential. At the same time symmetry in the electronic configuration of the elements also play a part in their ionization energy. Smaller the atomic size, greater will be the mutual electronic repulsion and lesser will be electron affinity. Similarly, the catenation which is a direct result of M - M bond strength is also affected by similar considerations.

The correct decreasing order of catenation among group $16$ elements is _________.

  1. $O > S > Se > Te$
  2. $S > O > Se > Te$
  3. $S > Se > Te > O$
  4. $S > Se > O > Te$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Power of self-catenation generally depends on bond strength (of M - M bond), so the decreasing order of catenation is :


                                  $S$               >                      $Se$           >          $ O$            >                $ Te$
Bond energy               226                                  172                       142                       126
($ kJ mol^{-1}$) 

The bond energy values generally decrease down the group But because of the very small size and consequent mutual inter electronic repulsion oxygen has lower bond energy than $S$ and $Se.$ Due to the large size, $Te - Te$ bond is the weakest.

Therefore, the correct decreasing order of catenation is- 

Multiple choice physics semiconductors band theory of solids, a brief introduction electron energies in solids energy bands

Which of the following has least band gap energy at $273K$.

  1. InSb

  2. InAs

  3. InP

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

The energy gaps of the given semiconductors at $273K$ are given:

   $InSb=0.16eV$ (Indium antimonide),
   $InAs=0.33eV$ (Indium arsenide),
   $InP=1.29eV$ (Indium phosphide),
  $GaSb=0.67eV$ (Galiumium antimonide),
It is clear that $InSb$ has the least energy gap.

Multiple choice chemistry the periodic table mendeleef's periodic table mendeleev's periodic law and its limitations mendeleev's periodic table development of the modern periodic table into the history

Most transition metals from multiple cations, that is, they have more than one possible amount of positive charge. Virtually all of the transition metals form dipositive $(2+)$ cations, along with one or more other forms. For example, titanium forms $Ti^{2+}$ ad $Ti^{4+}$, and cobalt forms $Co^{2+}$ and $Co^{3+}$.
The principal exceptions to this predominance of cations with a $2^{+}$ charge are scandium and yttrium, which form only tripositive cations. $Sc^{3+}$ and $Y^{3+}$, and copper and silver, which form cations with a single positive charge. $Cu^{+}$ and $Ag^{+}$.
[While copper also forms dipositive $Cu^{2+}$, silver exhibits the single positive state essentially exclusively.]
Which of the following offers a POSSIBLE explanation for the existence of $Cu^{+}$ and $Ag^{+}$?

  1. Mendeleev placed copper and silver in Group IB on his original periodic table because they formed compounds with the same combining ratios as elements in Group $1A$.

  2. Elemental copper and silver have a single valence electron, which is lost in cation formation.

  3. Copper and silver have higher ionization energies than the other transition metals in their respective periods, so are unable to lose more than one electron.

  4. The loss of one electron gives copper and silver noble gas configurations.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Configuration of Cu and Ag is $\left[ Ar \right] 3{ d }^{ 10 }4{ s }^{ 1 }$ and $\left[ Kr \right] 4{ d }^{ 10 }5{ s }^{ 1 }$ respectively. Thus both have $1$ valence electron which is lost in cation formation. Thus correct answer is option B.