JEE Questions for Chemistry Classification Of Elements And Periodicity In Properties Quiz 3 - MCQExams.com

In period atomic radii decreases from left to right as effective nuclear change increases.

So, Na is larger in size than Mg and neutral is larger than its positive ion.

On moving left to right along a period ionization energies increases. While it decreases in a group on moving downword. The IE of Be is greater than B due to completely filled s-orbital. Order of IE is as Be>B>Li>Na.

Element                    F        O      N       C

Electronegativity      4.0      3.5    3.1     2.5

Order of electronegativity is

F>O>N>C

F>N<O>C 

On moving top to down along a group atomic size increases. So, the amount of energy required for ejection of an electron from atom decreases i.e., ionization energy decreases. Hence order of IE, is

Li>Na>K>Cs

On moving left to right size decreases and nuclear charge increases. So, electron affinity get increases. But electron affinity of Nitrogen is very low due to extra stability of half filled 2p orbital order of electron affinity.

B<C<O>N.

Order of ionization energy

Be>Mg>Ca

Ionisation energy increases on moving down in a group and increases on moving left to right in a period.

Siderophiles are the elements which are collectively present in earth’s core. These are found in native found in native state. They have low reactivity.

With the discovery of inert gases, law of octaves lost its significance. It was now the 9^th element which had properties similar to first one.

“Metals are more than non metals”, this statement is incorrect.

Order of ionisation potential will be

Na<Al<Mg<Si

496<x<737<786

Sop ionization potential of Al will be in between 496 and 737. So it should be

575 KJ/mol.

Order of ionisation potential will be

Na<Al<Mg<Si

496<x<737<786

Sop ionization potential of Al will be in between 496 and 737. So it should be

575 KJ/mol.

Order of ionization energy

F<N<C<Be<B

Ionisation energy of Be and N is high due to stable configuration.

Order of ionisation energy Mg>Na

Ionisation energy increases on moving left to right in a period.

Eelctron affinity of fluorine is lower than that of chlorine due to very small size of fluorine.

In a given group, atomic size increases due to addition of extra shell which outweighs the effect of increased nuclear charge number of shells increase with addition of extra electrons. Hence, increase in atomic size down the group is due to increase in number of electron.