Periodic properties of the elements in the modern table

Assertion. ${\mathrm{Na}}^{+}$ and ${\mathrm{Al}}^{3+}$ are isoelectronic but the magnitude of the ionic radius of ${\mathrm{Al}}^{3+}$ is less than that of ${\mathrm{Na}}^{+}$ .

Reason. The magnitude of effective nuclear charge of the outer shell electrons in ${\mathrm{Al}}^{3+}$ is greater than in ${\mathrm{Na}}^{+}$ .

Pauling assumed that the electronegativity of hydrogen is 3 and calculated values of other elements with respect to this.

Give one disadvantage of Pauling scale of electronegativity.

Pauling assigned the electronegativity values for elements on the basis of ionisation energies. 

Mulliken scale of electronegativity is based on the concept of:

Give the relation between electronegativity, ionisation energy and electron affinity according to Mulliken.

The Mulliken scale simply considers the electronegativity of an element as the sum of the ionisation potential and the electron affinity of that element.

The metallic radius is half of the total distance between the nuclei of two adjacent atoms in a _____.

Mark the following statement as true or false.

Metallic radii increases across the period due to an increase in the effective nuclear charge.

How does metallic radius defined?

Arrange $\mathrm{B}\mathrm{e},\mathrm{}\mathrm{M}\mathrm{g},\mathrm{}\mathrm{C}\mathrm{a},\mathrm{}\mathrm{S}\mathrm{r}$ in the ascending order of ionisation enthalpy.

The correct order of $1^{\mathrm{st}}$ ionisation enthalpy among the following elements $\mathrm{Be}, \mathrm{B}, \mathrm{C}, \mathrm{N}, \mathrm{O}$ is

The electron affinity of bromine is $3.36 \mathrm{eV}$. How much energy in $\mathrm{kcal}$ is released when $8 \mathrm{g}$ of bromine is completely converted to ${\mathrm{Br}}^{-}$ ions in the gaseous state? ($1 \mathrm{eV}=23.06 \mathrm{kcal} {\mathrm{mol}}^{-1}$). (Give the value rounded-off to the nearest integer)

Amongst isoelectronic species, smaller the positive charge on the cation, smaller is the ionic radius.

Name the element with maximum electron affinity.

The atomic number of nitrogen is $7$. So, valency of nitrogen is $5$.

How ionisation energy varies from hydrogen to caesium?

Atomic numbers of five elements $\mathrm{A}, \mathrm{B}, \mathrm{C}, \mathrm{D}$ and $\mathrm{E}$ are $6, 8, 3, 7$ and $9$ respectively. Among these which elements have highest electropositivity?

$11, 12, 13$ and $14$ are the atomic numbers $\mathrm{Na}, \mathrm{Mg}, \mathrm{Al}$ and $\mathrm{Si}$ respectively. Which element have more atomic radius ?

Observe the given table and answer the following question:

The elements that belong to the same period are: