On the basis of quantum numbers, justify that the sixth period of… - Vidyadip

Question

On the basis of quantum numbers, justify that the sixth period of the periodictable should have 32 elements.

✓

Answer

In the periodic table of the elements, a period indicates the value of the principal quantum number (n) for the outermost shells. Each period begins with the filling of principal quantum number (n). The value of n for the sixth period is 6. For n = 6, azimuthal quantum number (l) can have values of 0, 1, 2, 3, 4.
According to Aufbau’s principle, electrons are added to different orbitals in order of their increasing energies. The energy of the 6d subshell is even higher than that of the 7s subshell.
In the $6^{th}$ period, electrons can be filled in only 6s, 4f, 5d, and 6 p subshells. Now, 6s has one orbital, 4f has seven orbitals, 5d has five orbitals, and 6p has three orbitals. Therefore, there are a total of sixteen (1 + 7 + 5 + 3 = 16) orbitals available. According to Pauli’s exclusion principle, each orbital can accommodate a maximum of 2 electrons. Thus, 16 orbitals can accommodate a maximum of 32 electrons.
Hence, the sixth period of the periodic table should have 32 elements.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "5 Marks Questions" from Classification of Elements and Periodicity in Properties→Classification of Elements and Periodicity in Properties — all question types→Chemistry STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

Complete the following equations for the reaction between
i. $\mathrm{Ca}+\mathrm{H}_2 \mathrm{O}$
ii. $\mathrm{Ca}(\mathrm{OH})_2+\mathrm{Cl}_2$
iii. $\mathrm{BeO}+\mathrm{NaOH}$
iv. $\mathrm{BaO}_2+\mathrm{H}_2 \mathrm{SO}_4$

Explain the following in contrast to alkynes: (i) Polymerisation (ii) Isomerisation (iii) Oxidation (iv) Ozonolysis

1. What is the general molecular formula of saturated monohydric alcohols?
2. Write structural formulae for compounds named as-
a. 1-Bromoheptane
b. 5-Bromoheptanoic acid

What does atomic radius and ionic radius really mean to you?

Show that the circumference of the Bohr orbit for the hydrogen atom is an integral multiple of the de Broglie wavelength associated with the electron revolving around the orbit.

1. Write all structural isomers of molecular formula $C _3 H _6 O$
2. Write resonance structures of $CH _3 COO ^{-}$and show the movement of electrons by curved arrows.

Write Lewis structure of the following compounds and show formal charge on each atom. $\mathrm{HNO}_3, \mathrm{NO}_2, \mathrm{H}_2 \mathrm{SO}_4$.

Balance the following reactions by ion electron method :
(a) $MnO _4^{-}+ H ^{+}+ Fe ^{2+} \longrightarrow Mn ^{2+}+ Fe ^{3+}+ H _2 O$
(b) $Cr _2 O _7^{2-}+ H ^{+}+ I ^{-} \longrightarrow Cr ^{3+}+ I _2+ H _2 O$

What is the type of hybridisation of carbon atoms marked with star.

$\text{CH}_{3}=\text{CH}-\text{C}-\text{O}-\text{H}$
$\text{CH}_{3}-\text{CH}_{2}-\text{OH}$
$\text{CH}_{3}-\text{CH}_{2}-\text{C}-\text{H}$
$\text{CH}_{3}-\text{CH}=\text{CH}-\text{CH}_{3}$
$\text{CH}_{3}-\text{C}\equiv\text{CH}$

Comprehension given below is followed by some multiple choice questions. Each question has one correct option. Choose the correct option.
Molecular orbitals are formed by the overlap of atomic orbitals. Two atomic orbitals combine to form two molecular orbitals called bonding molecular orbital (BMO) and anti bonding molecular orbital (ABMO). Energy of anti bonding orbital is raised above the parent atomic orbitals that have combined and the energy of the bonding orbital is lowered than the parent atomic orbitals. Energies of various molecular orbitals for elements hydrogen to nitrogen increase in the order.
Different atomic orbitals of one atom combine with those atomic orbitals of the second atom which have comparable energies and proper orientation. Further, if the overlapping is head on, the molecular orbital is called ‘Sigma’, and if the overlap is lateral, the molecular orbital is called ‘pi’. The molecular orbitals are filled with electrons according to the same rules as followed for filling of atomic orbitals. However, the order for filling is not the same for all molecules or their ions. Bond order is one of the most important parameters to compare the strength of bonds.

Why is benzene extra ordinarily stable though it contains three double bonds?