Classification of Elements and Periodicity in Properties Set-3

$\text{X}^{+}(\text{g}) + e^{-}$

$\text{X}^{-}(\text{g})$

$\text{X}^{2+}(\text{g}) + 2e^{-}$

$\text{X}(\text{l})$

They are located on the left side of the periodic table.

They can attain a stable noble gas electronic configuration by picking up one electron

They have high ionization enthalpies.

They are large atoms.

The added electron must enter the next higher principal quantum level ($n+1$), leading to a very unstable electronic configuration

They are monatomic.

They have small atomic radii.

Their ionization enthalpy is very low.

$\text{F}$

$\text{P}$

$\text{S}$

$\text{Cl}$ (Due to the larger $3p$ orbital accommodating the electron with less repulsion than $2p$ of $\text{F}$)

$\text{S}$ has a much smaller atomic radius than $\text{O}$.

The added electron in $\text{O}$ goes to the small $n=2$ quantum level and suffers significant electron-electron repulsion

$\text{O}$ is located lower in the group than $\text{S}$.

$\text{O}$ has a half-filled $p$-orbital.

Electronegativity is a measureable quantity, while $\Delta_{eg} H$ is not.

$\Delta_{eg} H$ measures energy change for an isolated gaseous atom forming an anion, while electronegativity is a measure of an atom's ability to attract shared electrons in a compound

Both measure the tendency to gain electrons, but $\Delta_{eg} H$ is qualitative.

$\Delta_{eg} H$ is expressed on the Pauling scale, while electronegativity is in $\text{kJ mol}^{-1}$.

The atomic radius decreases and the attraction between the valence electrons and the nucleus increases

The size of the atom increases.

Metallic properties increase.

Ionization enthalpy decreases.

Mulliken-Jaffe scale

Allred-Rochow scale

Pauling scale

Dobereiner scale

$\text{Na, Mg, Al}$

$\text{Si, P, S}$

$\text{C, N, O}$

$\text{F, Cl, Br}$ (Group 17, Halogens)

Must be highly negative.

Must be positive (endothermic), requiring energy to overcome repulsion between the incoming electron and the existing negative charge

Must be zero.

Is approximately equal to the first electron gain enthalpy.

$\text{Cl} > \text{F} > \text{O} > \text{N}$

$\text{F} > \text{N} > \text{O} > \text{Cl}$

$\text{F} > \text{O} > \text{N} > \text{Si}$

$\text{F} > \text{O} > \text{N} > \text{Cl}$ (Decreases down group, increases across period)

Element $\text{I}$

Element $\text{III}$

Element $\text{V}$ (Noble Gas: $\Delta_i H_1 = 2372, \Delta_{eg} H = +48$)

Element $\text{IV}$

Element $\text{III}$ (Halogen: $\Delta_i H_1 = 1681, \Delta_{eg} H = -328$)

Element $\text{IV}$

Element $\text{VI}$

Element $\text{I}$

$\text{H}$ and $\text{Li}$

$\text{O}$ and $\text{S}$

$\text{Cl}$ and $\text{Br}$

$\text{Na}$ and $\text{K}$

Eight minus the number of outermost electrons

Half the atomic number

The principal quantum number ($n$)

The group number divided by two