Q: Why Noble gases are usually have large atomic size in the period?

All the electrons of noble gas elements are paired(\$ns^{2}np^{6}\$ configuration), paired electrons produce inter electronic repulsions which weakens the effective nuclear force, so electrons tend to move away from the nucleus because of repulsions. So size of noble gases are bigger than the other elements in their respective periods.

Q: Which of the following noble gases has the highest positive electron gain enthalpy value?

Noble gas Electron gain enthalpy\$(kJ\ mol^{-1})\$\$He\$\$48\$\$Ne\$\$116\$\$Ar\$\$96\$\$Kr\$\$96\$\$Xe\$\$77\$

Q: The first noble gas compound prepared by Bartlett is :

\$XePtF_6\$ was the first noble gas prepared by Bartlett.Option C is correct.

Q: Which of the following substance will have highest boiling point?

Boiling point \$\times \$ Molar mass \$\times \$ Ionic characterwhich is highest for \$CsF\$

Question 1

Which of the following exhibits the weakest intermolecular forces?

Accepted Answer

Hint: London dispersion force is the weakest intermolecular force.Explanation:There are three major intermolecular forces that act on the compound such as;London dispersion forces, Dipole-Dipole interactions, and hydrogen bonding.Among those, the London dispersion forces are the weakest while hydrogen bonding is the strongest of all.Hydrogen bonding is formed by the elements $N, O,F$ when attached to $H$.So, here in the case of $H_2O$ and $NH_3$ hydrogen bonding is present.In the case of $HCl$, we have a dipole-dipole interaction present due to the electronegativity difference between $H$ and $Cl$.Helium is the noble gas element and there are no attractive forces that exist in them except London dispersion. So, $He$ has London dispersion force which is the weakest intermolecular force.Correct Option: $C$

Question 2

What were the reasons for late discovery of noble gases?

Accepted Answer

The reasons for late discovery of noble gases:Chemical inertness of lighter noble gases, i.e., He, Ne and Ar,Rare abundance of comparatively reactive noble gases, i.e., Kr, Xe and Rn Hence options A  & B are correct

Question 3

In the preparation of compounds of Xe, Bartlett had taken $O_{2}^{+} PtF_{6}^{-}$ as a base compound. This is because:

Accepted Answer

&#10;&#10;bartlett observed  that the first ionization potential of Xenon is almost equals to that of the Oxygen molecule and made  Born-Haber calculation&#10;to predict that there would be a stable compound: $Xe^{+} PtF_6^{-}$.Hence option C is correct.&#10;&#10;

Question 4

What are noble gases? Why are they also called inert gases?

Accepted Answer

Noble gases belong to the 18th group of the periodic table. They include helium, neon, argon, krypton, xenon and radon. They are called inert gases because they are stable and non-reactive.

Question 5

Why Noble gases are usually have large atomic size in the period?

Accepted Answer

&#10;&#10;All the electrons of noble gas elements are paired($ns^{2}np^{6}$&#10;configuration), paired electrons produce  inter electronic repulsions which weakens the&#10;effective nuclear force, so electrons tend to move  away from the nucleus because of repulsions.&#10;So size of noble gases are bigger than the other elements in their respective&#10;periods.&#10;&#10;

Question 6

Which of the following noble gases has the highest positive electron gain enthalpy value?

Accepted Answer

Noble gas         Electron gain enthalpy$(kJ\ mol^{-1})$$He$$48$$Ne$$116$$Ar$$96$$Kr$$96$$Xe$$77$

Question 7

The first noble gas compound prepared by Bartlett is :

Accepted Answer

$XePtF_6$ was the first noble gas prepared by Bartlett.Option C is correct.

Question 8

Helium is used in balloons in place of hydrogen because it is:

Accepted Answer

Helium is used in balloons in place of hydrogen because it&#10;is incombustible. $He$  do not catch fire like hydrogen. $He$ is a inert element. Hence, option A is correct.

Question 9

Which of the following substance will have highest boiling point?

Accepted Answer

Boiling point $\times $ Molar mass $\times $ Ionic characterwhich is highest for $CsF$

Question 10

List the uses of neon and argon gases.

Accepted Answer

Uses of Neon:(i) To fill discharge tubes for optical decorations and advertisements. (ii) In neon bulbs, botanical gardens and green houses. (iii) It can carry extremely high currents even under high voltage. Hence, it is used in safety devices for protecting electrical instruments such as voltmeters, relays, rectifiers etc.(iv) To fill sodium vapor lamps.(v) in becon light as a safety signal for air navigators as its light has fog penetration power.Uses of Argon:(i) Due to inert nature, it is used to fill electric bulb. (ii) To provide inert atmosphere in high temperature metallurgical processes (arc welding of metals or alloys).(iii) Pure argon is used in gas chromatography.(iv) To handle air sensitive substances in laboratory.(v) To protect metal surfaces from oxidation during steel welding.

Revise with Concepts

General Properties of Group 18 Elements

Chemical Properties of Group 18 Elements

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Quick Summary With Stories

Group 18 Elements - Physical and Atomic Properties

Group 18 Elements - Chemical Properties

Which of the following exhibits the weakest intermolecular forces?

What were the reasons for late discovery of noble gases?

In the preparation of compounds of Xe, Bartlett had taken $O_{2}^{+} P t F_{6}^{-}$ as a base compound. This is because:

What are noble gases? Why are they also called inert gases?

Why Noble gases are usually have large atomic size in the period?

Which of the following noble gases has the highest positive electron gain enthalpy value?

The first noble gas compound prepared by Bartlett is :

Helium is used in balloons in place of hydrogen because it is:

Which of the following substance will have highest boiling point?

List the uses of neon and argon gases.

Revise with Concepts

General Properties of Group 18 Elements

Chemical Properties of Group 18 Elements

Learn with Videos

Quick Summary With Stories

Group 18 Elements - Physical and Atomic Properties

Group 18 Elements - Chemical Properties

Which of the following exhibits the weakest intermolecular forces?

What were the reasons for late discovery of noble gases?

In the preparation of compounds of Xe, Bartlett had taken O2+​PtF6−​ as a base compound. This is because:

What are noble gases? Why are they also called inert gases?

Why Noble gases are usually have large atomic size in the period?

Which of the following noble gases has the highest positive electron gain enthalpy value?

The first noble gas compound prepared by Bartlett is :

Helium is used in balloons in place of hydrogen because it is:

Which of the following substance will have highest boiling point?

List the uses of neon and argon gases.

In the preparation of compounds of Xe, Bartlett had taken $O_{2}^{+} P t F_{6}^{-}$ as a base compound. This is because: