Question

Arrange the following elements in order of decreasing Atomic radii,first ionization energy and electro negativity. Justify your answers
K,P, F, Mg

Answer 1

$\bold{ELEMENTS :- K, P, F, Mg}$

$\bold{Atomic \: radius}$

The distance between the centre of nucleus to the outermost shell is know as atomic radius.

Its dependent :-

▶Nuclear charge -- It increases more will be the nuclear attraction , electrons will be attrac toward the nucleus hence atomic radius will increase.

▶Number of shells -- More the number of shells, more will be the distance between centre of nucleus , more will be the atomic radius.

So,

◼In a peroid --Number of electrons increases and and no of shells remains same therefore atomic radius decreases.

◼In a group --Number of electrons increases a number of shells also increases .Since, number of shells dominates over nuclear charge therefore it increases through a period .

SO,

ELEMENTS WILL BE IN :-

$\huge \boxed{K, Mg, P, F}$

$\bold{IONISATION \: POTENTIAL }$

It is the amount of energy required to remove a loosely bound electron from the outermost shell of an isolated gaseous atom.

Its dependent

◼Nuclear charge -- More the nuclear attraction more tightly the electron will be held and will be more difficult to be loosed therefore ionisation potential will increase.

◼Atomic radius --More will the atomic radius the electron will be losely held so ionisation potential will decrease.

▶In period -- Nuclear charge increases and atomic radius decreases therefore ionisation potential increases.

▶In a group -- Atomic radius increases and nuclear charge also increases but atomic radius dominates over nuclear charge therefore ionisation potential decreases.

SO,

ELEMENTS WILL BE IN :-

$\huge \boxed{F, P, Mg, K}$

$\bold{ELECTRONEGATIVITY }$

Its the tendency of an atom to attract electrons itself when combined in a compound.

Its dependent

◼Nuclear charge -- Nuclear charge increases so atom will attract electrons towards itself so electronegativity will increase.

◼Atomic radius -- The more will be the atomic radius the less will be the electron negativity .

▶In a period - Nuclear charge increases and atomic radius decreases so electron negativity increases.

▶In group - Nuclear charge increases and atomic radius increases since atomic radius dominates over nuclear charge therefore electron negativity decreases.

SO,

ELEMENTS WILL BE IN :-

$\huge \boxed{K,Mg,P , F}$