Arrange the following sets of elements in order of increasing atomic size.

msp;  a .  Sn ,  Xe ,  R b .  Srb .  Rn ,  He ,  Xe ,  Kr c .  Pb ,  Ba ,  Cs ,  At

(a)

Interpretation:

The increasing order of atomic size of the elements is to be stated.

Concept Introduction:

The distance of the valence shell from the nucleus is known as Atomic size. On going down the group, the force of attraction between the nucleus and valence electrons in an atom decreases as the number of valence shells increases. This is the reason that atomic size increases. On going across the period, the force of attraction between the nucleus and valence electrons in an atom increases as the number of valence electrons increases in the same shell. This is the reason that atomic size decreases.

On going across the period, the force of attraction between the nucleus and the valence electrons in an atom increases as the number of valence electrons in the same shell increases. This is the reason that atomic size decreases across the period...

(b)

Interpretation:

The increasing order of atomic size of the elements is to be stated.

Concept Introduction:

The distance of the valence shell from the nucleus is known as Atomic size. On going down the group, the force of attraction between the nucleus and valence electrons in an atom decreases as the number of valence shells increases. This is the reason that atomic size increases. On going across the period, the force of attraction between the nucleus and valence electrons in an atom increases as the number of valence electrons increases in the same shell. This is the reason that atomic size decreases.

(c)

Interpretation:

The increasing order of atomic size of the elements is to be stated.

Concept Introduction:

The distance of the valence shell from the nucleus is known as Atomic size. On going down the group, the force of attraction between the nucleus and valence electrons in an atom decreases as the number of valence shells increases. This is the reason that atomic size increases. On going across the period, the force of attraction between the nucleus and valence electrons in an atom increases as the number of valence electrons increases in the same shell. This is the reason that atomic size decreases.