Modern Periodic Law and the Present Form of the Periodic Table

Assertion (A) : Sixth period is the longest period in the periodic table.

Reason (R) : Sixth period involves the filling of all the orbitals of the sixth energy level.

The atomic number of element $\mathrm{Unq}$ is

The IUPAC name for the element with the atomic number $120$ is _____.

The correct order of filling up of subshells in the seventh period is

All the lanthanoids and actinoids belong to group _____ of the periodic table.($3/4$).

The first member of lanthanoid series is lanthanum.

All the lanthanoids and actinoids belong to group _____ of the periodic table.($3/4$)

Elements having the similar outer electronic configuration in their atoms are arranged in the same _____.

The atomic number of element $\mathrm{Unq}$ is

Which of the following groups does helium belongs?

All of the group$-\mathrm{I}$ elements have ${\mathrm{ns}}^1$ valence shell electronic configuration and the properties of an element have

Which of the following statement is incorrect?

$3\mathrm{d}-$transition series of elements start with scandium which has the electronic configuration

Successive filling of $3\mathrm{s}$ and $3\mathrm{p}-$orbitals give rise to the third period. The number of elements present in this period are 

An element $\mathrm{A}$ belongs to third period and fifteenth group of the periodic table. Which one of the following is true regarding the outer electronic configuration of $\mathrm{A}$?

The fifteen elements from Lanthanum to Lutetium are named as _____

IUPAC name of the element with atomic number $110$ is _____

An element has its electronic configuration as 2, 8, 2. What is the group of this element?

In Lanthanoid series, the element well known to exhibit $+4$ oxidation state is

Henry Moseley plotted a graph between $\sqrt{\mathrm{\nu }}$ and $\mathrm{Z}$, where $\mathrm{\nu }$ was the frequency of $\mathrm{X}-$ray and $\mathrm{Z}$ was its atomic number.This graph showed that