Q: In the third excited state, the number of unpaired electrons in chlorine atom is:

The general electronic configuration of chlorine is \$[Ne] 3s^{2} 3p^{5}\$.When electrons are excited in chlorine, the electrons enter into 3d subshell then the electronic configuration of chlorine is given as:\$[Ne] 3s^{1} 3p^{3} 3d^{3}\$Thus the number of unpaired electrons will be 7.

Q: If a new noble gas is discovered then, what will be its atomic number?

\$Rn+32 = 86+ 32 = 118\$The atomic number of next inert gas to be discovered will be \$118\$.

Q: The elements with atomic numbers \$2, 10, 18, 36, 54\$ and \$86\$ are collectively known as:

Zero group of Mendeleev's periodic table or the group \$18\$ of long form of periodic table is comprised of six elements and these eleements are called as inert gases as trhese elements do not react (inert) with other elements due to their octet outer electronic configaration which is stable configaration. The electronic configuration is listed in the following table. S.No Element Symbol Atomic no. Electronic configuration1 Helium He 2 1s\$^2\$2 Neon Ne 10 [He] 2s\$^2\$2p\$^6\$3 Argon Ar 18 [Ne] 3s\$^2\$3p\$^6\$ 4 Krypton Kr 36 [Ar] 3d\$^{10}\$4s\$^2\$4p\$^6\$ 5 Xenon Xe 54 [Kr] 4d\$^{10}\$5s\$^2\$5p\$^6\$ 6 Radon Rn 86 [Xe] 4f\$^{14}\$5d\$^{10}\$6s\$^2\$6p\$^6\$

Q: The inert gas atom in which the total number of d-electrons is equal to the difference in numbers of total \$p-\$ and \$s-\$electrons, is:

\$He, Ne\$ and \$Ar\$ do not have any \$d\$ electrons, while the difference of their \$s\$ and \$p\$ electrons is not zero. The electronic configuration of krypton (atomic number is 36) is: \$1s^2,2s^2,2p^6,3s^2,3p^6,3d^{10},4s^2,4p^6\$.Total \$s-\$electrons are 8 and total \$p-\$electrons are 18.Thus, the difference is 10 and total d-electrons are 10 which are equal.So, option \$D\$ is correct answer.

Q: Elements with atomic numbers 9, 17, 35, 53 are collectively known as:

Elements having the atomic number:9 is fluorine: \$(He)2s^22p^5\$17 is chlorine: \$(Ne)3s^23p^5\$35 is bromine: \$(Ar)4s^24p^5\$53 is iodine: \$(Kr)5s^25p^5\$We can observe here that all these elements having the general electronic configuration of \$ns^2np^5\$, hence these elements belong to \$17^{th}\$ group elements.

Q: The inert gas present in the second long period is:

Periods \$4\$ and \$5\$ are called long periods as they contain \$18\$ elements each. \$4\$th period is called the first long period and the inert gas in this period is \$Kr\$.\$5\$th period is the second long period where \$Xe\$ is the inert gas element.

Question 1

In the third excited state, the number of unpaired electrons in chlorine atom is:

Accepted Answer

The general electronic configuration of chlorine is $[Ne] 3s^{2} 3p^{5}$.When electrons are excited in chlorine, the electrons enter into 3d subshell then the electronic configuration of chlorine is given as:$[Ne] 3s^{1} 3p^{3} 3d^{3}$Thus the number of unpaired electrons will be 7.

Question 2

If a new noble gas is discovered then, what will be its atomic number?

Accepted Answer

$Rn+32 = 86+ 32 = 118$The atomic number of next inert gas to be discovered will be $118$.

Question 3

Which of the following electronic configuration corresponds to an inert gas?

Accepted Answer

Noble gases have full-filled configuration i.e the subshell are completely filled.They have the general electronic configuration as $ns^2 np^6$. Thus option B represents a noble gas.

Question 4

Mono atomic element among the following is:

Accepted Answer

Oxygen is diatomic gas.  Phosphorous is tetra atomic.Sulphur is polyatomic.Whereas being an inert gas, Krypton is monoatomic.

Question 5

The elements with atomic numbers $2, 10, 18, 36, 54$ and $86$ are collectively known as:

Accepted Answer

Zero group of Mendeleev's periodic table or the group $18$ of long form of periodic table is comprised of six elements and these eleements are called as inert gases as trhese elements do not react (inert) with other elements due to their octet outer electronic configaration which is stable configaration. The electronic configuration is listed in the following table.          S.No   Element    Symbol  Atomic no. Electronic  configuration1    Helium    He   2   1s$^2$2    Neon    Ne   10   [He] 2s$^2$2p$^6$3    Argon    Ar   18   [Ne] 3s$^2$3p$^6$            4    Krypton    Kr   36               [Ar] 3d$^{10}$4s$^2$4p$^6$                                            5    Xenon    Xe   54               [Kr] 4d$^{10}$5s$^2$5p$^6$                      6    Radon    Rn    86   [Xe] 4f$^{14}$5d$^{10}$6s$^2$6p$^6$

Question 6

The inert gas atom in which the total number of d-electrons is equal to the difference in numbers of total $p-$ and $s-$electrons, is:

Accepted Answer

$He, Ne$ and $Ar$ do not have any $d$ electrons, while the difference of their $s$ and $p$ electrons is not zero. The electronic configuration of krypton (atomic number is 36) is: $1s^2,2s^2,2p^6,3s^2,3p^6,3d^{10},4s^2,4p^6$.Total $s-$electrons are 8 and total $p-$electrons are 18.Thus, the difference is 10 and total d-electrons are 10 which are equal.So, option $D$ is correct answer.

Question 7

Elements O, S, Se and Te are commonly known as:

Accepted Answer

O, Se, S and Te belongs VI group or 16th group of the periodic table.$\therefore  $ Commonly known as chalcogens.Option C is correct.

Question 8

According to Coulson the high reactivity of fluorine than other halogens is because of its:

Accepted Answer

According to Coulson, since fluorine atoms are small it's intermolecular repulsion is appreciable. The large electron-electron repulsion between the lone pairs of electrons on the fluorine atom weakens the bond.

Question 9

Elements with atomic numbers 9, 17, 35, 53 are collectively known as:

Accepted Answer

Elements having the atomic number:9 is fluorine: $(He)2s^22p^5$17 is chlorine: $(Ne)3s^23p^5$35 is bromine: $(Ar)4s^24p^5$53 is iodine: $(Kr)5s^25p^5$We can observe here that all these elements having the general electronic configuration of $ns^2np^5$, hence these elements belong to $17^{th}$ group elements.

Question 10

The inert gas present in the second long period is:

Accepted Answer

Periods $4$ and $5$ are called long periods as they contain $18$ elements each. $4$th period is called the first long period and the inert gas in this period is $Kr$.$5$th period is the second long period where $Xe$ is the inert gas element.

The P Block Elements

Chemistry
6762 Views

In the third excited state, the number of unpaired electrons in chlorine atom is:

If a new noble gas is discovered then, what will be its atomic number?

Which of the following electronic configuration corresponds to an inert gas?

Mono atomic element among the following is:

The elements with atomic numbers $2, 10, 18, 36, 54$ and $86$ are collectively known as:

The inert gas atom in which the total number of d-electrons is equal to the difference in numbers of total $p -$ and $s -$ electrons, is:

Elements O, S, Se and Te are commonly known as:

According to Coulson the high reactivity of fluorine than other halogens is because of its:

Elements with atomic numbers 9, 17, 35, 53 are collectively known as:

The inert gas present in the second long period is:

The P Block Elements

Chemistry 6762 Views

In the third excited state, the number of unpaired electrons in chlorine atom is:

If a new noble gas is discovered then, what will be its atomic number?

Which of the following electronic configuration corresponds to an inert gas?

Mono atomic element among the following is:

The elements with atomic numbers 2,10,18,36,54 and 86 are collectively known as:

The inert gas atom in which the total number of d-electrons is equal to the difference in numbers of total p− and s−electrons, is:

Elements O, S, Se and Te are commonly known as:

According to Coulson the high reactivity of fluorine than other halogens is because of its:

Elements with atomic numbers 9, 17, 35, 53 are collectively known as:

The inert gas present in the second long period is:

Chemistry
6762 Views

The elements with atomic numbers $2, 10, 18, 36, 54$ and $86$ are collectively known as:

The inert gas atom in which the total number of d-electrons is equal to the difference in numbers of total $p -$ and $s -$ electrons, is: