Element O B C N Be Li Atomic radius (pm) 66 88 77 74 111 152 By referring to the modern periodic table find out the periods to which the above elements belong.

The elements like lithium, beryllium, boron, carbon, nitrogen, oxygen belongs to the second period of the modern periodic table.

Element O B C N Be Li Atomic radius (pm) 66 88 77 74 111 152 Arrange the above elements in decreasing order of their atomic radii.

The atomic radii is decreases on moving from left to right in a period of the periodic table. As moving from left to right in a period, the atomic number of elements increases by one. As atomic number increases, nuclear charge also increases. Because of this increased nuclear charge, the electrons are attracted strongly towards the nucleus and hence the atomic size decreases. Arrangement of elements in decreasing order of atomic radius Li Be B C N O Atomic radius (pm) 152 111 88 77 74 66

Element O B C N Be Li Atomic radius (pm) 66 88 77 74 111 152 Does this arrangement match with the pattern of the second period of the modern periodic table?

The arrangements match with the second period because all the elements given in this series have two energy shells or orbits present in their atoms.

Element O B C N Be Li Atomic radius (pm) 66 88 77 74 111 152 Which of the above elements have the biggest and the smallest atom?

The lithium is the biggest atom and the oxygen is the smallest atom in the given list. The size of the atom depends upon the distance between the central nucleus to the outermost orbit. In a period from left to right atomic size decreases.

Element K Na Rb Cs Li Atomic radius (pm) 231 186 244 262 152 By referring to the modern periodic table find out the group to which above the elements belong

The elements like potassium, sodium, rubidium, caesium, lithium belongs to the first group of the modern periodic table. All elements in group 1 have 1 valence electron, so they have a valency of + 1 as they will tend to give up 1 electron.

MEDIUM

10th Maharashtra Board

IMPORTANT

Earn 100

Write the electronic configuration of the first $20$ elements, symbol, and write the valency. Make the table on the basis of the modern periodic table.

Important Questions on Periodic Classification of Elements

MEDIUM

10th Maharashtra Board

IMPORTANT

Science and Technology Standard Ten Part - 1>Chapter 2 - Periodic Classification of Elements>Think about it>Q 4

What is the periodic trend in the variation of valency while going from left to right within a period? Explain your answer with reference to period

2

and period

3

MEDIUM

10th Maharashtra Board

IMPORTANT

Science and Technology Standard Ten Part - 1>Chapter 2 - Periodic Classification of Elements>Think about it>Q 5

What is the periodic trend in the variation of valency while going down a group? Explain your answer with reference to the group

3

, group

2

and group

Si

EASY

10th Maharashtra Board

IMPORTANT

Science and Technology Standard Ten Part - 1>Chapter 2 - Periodic Classification of Elements>Use your brain power>Q 1

Element	$O$	$B$	$C$	$N$	$Be$	$2$
Atomic radius (pm)	$66$	$88$	$77$	$1$	$111$	$152$

By referring to the modern periodic table find out the periods to which the above elements belong.

MEDIUM

10th Maharashtra Board

IMPORTANT

Science and Technology Standard Ten Part - 1>Chapter 2 - Periodic Classification of Elements>Use your brain power>Q 2

Element	$O$	$B$	$C$	$N$	$Be$	$2$
Atomic radius (pm)	$66$	$88$	$77$	$74$	$111$	$152$

Arrange the above elements in decreasing order of their atomic radii.

MEDIUM

10th Maharashtra Board

IMPORTANT

Science and Technology Standard Ten Part - 1>Chapter 2 - Periodic Classification of Elements>Use your brain power>Q 3

Element	$O$	$B$	$C$	$N$	$Be$	$Li$
Atomic radius (pm)	$66$	$88$	$77$	$74$	$111$	$152$

Does this arrangement match with the pattern of the second period of the modern periodic table?

MEDIUM

10th Maharashtra Board

IMPORTANT

Science and Technology Standard Ten Part - 1>Chapter 2 - Periodic Classification of Elements>Use your brain power>Q 4

Element	$O$	$B$	$C$	$N$	$Be$	$Li$
Atomic radius (pm)	$66$	$88$	$77$	$74$	$111$	$152$

Which of the above elements have the biggest and the smallest atom?

MEDIUM

10th Maharashtra Board

IMPORTANT

Science and Technology Standard Ten Part - 1>Chapter 2 - Periodic Classification of Elements>Use your brain power>Q 5

Element	$O$	$B$	$C$	$N$	$Be$	$Li$
Atomic radius (pm)	$66$	$88$	$77$	$74$	$111$	$152$

What is the periodic trend observed in the variation of atomic radius while going from left to right within a period?

EASY

10th Maharashtra Board

IMPORTANT

Science and Technology Standard Ten Part - 1>Chapter 2 - Periodic Classification of Elements>Use your brain power>Q 1

Element	$K$	$Na$	$Rb$	$Cs$	$Li$
Atomic radius (pm)	$231$	$186$	$244$	$262$	$152$

By referring to the modern periodic table find out the group to which above the elements belong

Write the electronic configuration of the first 20 elements, symbol, and write the valency. Make the table on the basis of the modern periodic table.

Important Questions on Periodic Classification of Elements

Learn and Prepare for any exam you want !

Write the electronic configuration of the first $20$ elements, symbol, and write the valency. Make the table on the basis of the modern periodic table.