The atomic radii of the elements of the second period are given below:
Second period elements$B$$Be$$O$$N$$Li$$F$$C$
Atomic Radii $(pm)$$88$$111$$66$$74$$152$$64$$77$

$(i)$ Arrange these elements in decreasing order of their atomic radii.
$(ii)$ Are the elements now arranged in the pattern of a period in the periodic table?
$(iii)$ Name the element which has the $(a)$ smallest and $(b)$ largest atomic number.
$(iv)$ From the above data, infer how the atomic size or atomic radius of the elements changes as we move from left to right in a period.
$(v)$ Name one metal, one non-metal, and a metalloid out of these elements.
$(vi)$ Why does atomic radius decrease as we move from left to right in a period?

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(N/A) $(i)$ The decreasing order of atomic radii is: $Li (152) > Be (111) > B (88) > C (77) > N (74) > O (66) > F (64)$.
$(ii)$ Yes, the elements are now arranged in the order of a period in the periodic table (from left to right).
$(iii)$ $(a)$ The element with the smallest atomic number is $Li$ (atomic number $3$).
$(b)$ The element with the largest atomic number is $F$ (atomic number $9$).
$(iv)$ From the data, we can infer that the atomic radius decreases as we move from left to right in a period.
$(v)$ Metal: $Li$ (Lithium), Non-metal: $F$ (Fluorine), Metalloid: $B$ (Boron).
$(vi)$ As we move from left to right in a period, the nuclear charge increases due to the addition of protons in the nucleus. This increased nuclear charge pulls the valence electrons closer to the nucleus, resulting in a decrease in atomic radius.

Explore More

Similar Questions

$(a)$ State the main characteristics of elements on which the modern periodic table is based.
$(b)$ No fixed position can be assigned to hydrogen in the periodic table. Why?

An element $X$ belongs to the $3rd$ period and group $16$ of the Modern Periodic Table.
$(a)$ Determine the number of valence electrons and the valency of $X$.
$(b)$ Write the molecular formula of the compound formed when $X$ reacts with hydrogen and draw its electron dot structure.
$(c)$ Name the element $X$ and state whether it is metallic or non-metallic.

$(a)$ Electropositive nature of the element$(s)$ increases down the group and decreases across the period.
$(b)$ Electronegativity of the element decreases down the group and increases across the period.
$(c)$ Atomic size increases down the group and decreases across a period (left to right).
$(d)$ Metallic character increases down the group and decreases across a period.
On the basis of the above trends of the Periodic Table,answer the following about the elements with atomic numbers $3$ to $9$:
$(a)$ Name the most electropositive element among them.
$(b)$ Name the most electronegative element.
$(c)$ Name the element with the smallest atomic size.
$(d)$ Name the element which is a metalloid.
$(e)$ Name the element which shows maximum valency.

Difficult
View Solution

Properties of the elements are given below. Where would you locate the following elements in the periodic table?
$(a)$ An element which is an inert gas with atomic number $2$.
$(b)$ An element whose thin oxide layer is used to make other elements corrosion resistant by the process of 'anodising'.

Arrange the following elements in the order of their decreasing metallic character: $Na, Si, Cl, Mg, Al$.

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo