Which among the following is correct regarding Ne 20 , Na + 23 , 19 F - and Mg 2 + 24 ?

They are isoelectronic with each other.

They are isomers of each other.

They are isotopes of each other.

HARD

NDA & NA EE

IMPORTANT

Earn 100

All the elements in a group (family) have a common valency. For example, all the elements of the carbon family (carbon, silicon, germanium, tin and lead) have the common valency four. However, some of these elements can also have a valency two. Which of the following have a valency two?

50% studentsanswered this correctly

Important Questions on Periodic Classification of Elements

MEDIUM

NDA & NA EE

IMPORTANT

Pathfinder NDA / NA National Defence Academy and Naval Academy Entrance Examination Chemistry>Chapter 6 - Periodic Classification of Elements>Practice Exercise>Q 36

The best and the poorest conductors of heat, respectively, are:

MEDIUM

NDA & NA EE

IMPORTANT

Pathfinder NDA / NA National Defence Academy and Naval Academy Entrance Examination Chemistry>Chapter 6 - Periodic Classification of Elements>Practice Exercise>Q 37

Match List $I$ with List $II$ and select the correct combination of ions and isoelectronic ions using the codes given below the lists.

List $I$		List $II$
A.	${SO}_{2}$	1.	$CO$
B.	$N_{2}$	2.	${Cl}^{-}$
C.	$H^{-}$	3.	${CO}_{3}^{2 -}$
D.	$K^{+}$	4.	${Li}^{+}$

HARD

NDA & NA EE

IMPORTANT

Pathfinder NDA / NA National Defence Academy and Naval Academy Entrance Examination Chemistry>Chapter 6 - Periodic Classification of Elements>Practice Exercise>Q 38

Match the properties given in Column $I$ with the metals given in Column $II$ and choose the correct option from the codes given below.

Column $I$ (Property)		Column $II$ (Metal)
A.	Element with the highest second ionisation enthalpy	$1$ .	$Co$
B.	Element with the highest third ionisation enthalpy	$2$ .	$Cr$
C.	$M$ in $M {(CO)}_{6}$ is	$3$ .	$Cu$
D.	Element with the highest heat of atomisation	$4$ .	$Zn$

EASY

NDA & NA EE

IMPORTANT

Pathfinder NDA / NA National Defence Academy and Naval Academy Entrance Examination Chemistry>Chapter 6 - Periodic Classification of Elements>Practice Exercise>Q 40

Which one of the following elements exists in the liquid state at room temperature?

MEDIUM

NDA & NA EE

IMPORTANT

Pathfinder NDA / NA National Defence Academy and Naval Academy Entrance Examination Chemistry>Chapter 6 - Periodic Classification of Elements>Practice Exercise>Q 41

Which among the following is correct regarding ${}^{20}{Ne}, {}^{23}{Na}^{+}, {}^{19} F^{-}$ and ${}^{24}{Mg}^{2 +} ?$

EASY

NDA & NA EE

IMPORTANT

Pathfinder NDA / NA National Defence Academy and Naval Academy Entrance Examination Chemistry>Chapter 6 - Periodic Classification of Elements>Practice Exercise>Q 42

Which of the following pairs represents isoelectronic ions?

MEDIUM

NDA & NA EE

IMPORTANT

Pathfinder NDA / NA National Defence Academy and Naval Academy Entrance Examination Chemistry>Chapter 6 - Periodic Classification of Elements>Practice Exercise>Q 43

Match List $I$ with List $II$ and select the correct answer using the codes given below the lists.

List $I$ (Element)		List $II$ (Use)
A.	$Li$	1.	Timekeeper in atomic clocks
B.	$Na$	2.	Batteries
C.	$K$	3.	Transfer of nerve impulses
D.	$Cs$	4.	Control of the water content in the blood

HARD

NDA & NA EE

IMPORTANT

Pathfinder NDA / NA National Defence Academy and Naval Academy Entrance Examination Chemistry>Chapter 6 - Periodic Classification of Elements>Practice Exercise>Q 44

The alkali metals have relatively low melting point. Which one of the following alkali metals is expected to have the highest melting point?

All the elements in a group (family) have a common valency. For example, all the elements of the carbon family (carbon, silicon, germanium, tin and lead) have the common valency four. However, some of these elements can also have a valency two. Which of the following have a valency two?

Important Questions on Periodic Classification of Elements

Learn and Prepare for any exam you want !