Q: The electron affinity values (kJmol\$^{-1}\$) of three halogens \$X,\ Y \$ and \$Z\$ respectively are \$-349\$, \$-333 \$ and \$-325\$. Then \$X,\ Y \$ and \$Z\$ respectively are :

Order of \$EA\$ of halogens is \$Cl>F>Br\$.Hence, the value of \$EA\$ will be that of \$Cl_2\$, \$F_2\$, \$Br_2\$ respectively.

Question 1

In Mendeleev table, the triad of VIII group is :

Accepted Answer

Group VIII of Mendeleev's table consists of three triads known as transition triads and they are i) Iron, Cobalt, and Nickelii) Ruthenium, Rhodium, and Palladiumiii) Osmium, Iridium, and PlatiniumOption $A$ is correct.

Question 2

All elements of the same group will have:

Accepted Answer

All the elements in a group having the same number of valence electrons and hence have a similar outer electronic configuration.Hence, the correct option is $\text{B}$

Question 3

Identify the property which does not reflect the periodicity of the elements.

Accepted Answer

Neutron to proton ratio is not a periodic property as it is not having any regular trend where as the remaining options have a regular trend in groups as well as periods.

Question 4

The low electron affinity value of nitrogen is due to :

Accepted Answer

Nitrogen atom, in its ground state, has a stable half-filled configuration of $1s^2$$2s^2$$2p^3$. 2p subshell is half-filled in the atom. Hence, its electron affinity is low.

Question 5

Which of the following has zero electron affinity?

Accepted Answer

Noble gases or inert gases do not have a tendency to gain an electron. Hence, its electron affinity is zero.

Question 6

The electron affinity values (kJmol$^{-1}$) of three halogens $X,\ Y $ and $Z$ respectively are $-349$, $-333 $ and $-325$. Then $X,\ Y $ and $Z$ respectively are :

Accepted Answer

Order of $EA$ of halogens is $Cl>F>Br$.Hence, the value of $EA$ will be that of $Cl_2$, $F_2$, $Br_2$ respectively.

Question 7

Number of short periods in Mendeleev's periodic table is :

Accepted Answer

Period number 1, 2 and 3 contain 2, 8 and 8 elements respectively. Other periods contain more than 8 elements. Hence, the first three periods are called as short periods. So, total of 3 short periods are there in Mendeleev periodic table.

Question 8

Considering the chemical properties, atomic weight of $Be$ was corrected based on:

Accepted Answer

The atomic weight of Be was corrected based on:Atomic weight $=$ equivalent weight $\times$ valencyFrom this, we can understand that the atomic weight of $Be$ was corrected based on valency.

Question 9

What is the atomic number of another element present in the same group as the element with $Z = 13$?

Accepted Answer

An element having atomic no. 13 is present in the 3rd period. Now, next element will have atomic number $13 + 18 = 31$. After that element, another element will have atomic number $31 + 18 = 49$.

Question 10

In a period, elements are arranged strictly in a sequence of:

Accepted Answer

In a period, the elements are arranged strictly in a sequence of increase in atomic number by one unit, i.e., increase in a number of protons by one and thereby increase in charge in the nucleus by one unit.Option B is correct.

Classification Of Elements And Periodicity In Properties

Chemistry
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In Mendeleev table, the triad of VIII group is :

All elements of the same group will have:

Identify the property which does not reflect the periodicity of the elements.

The low electron affinity value of nitrogen is due to :

Which of the following has zero electron affinity?

The electron affinity values (kJmol $^{- 1}$ ) of three halogens $X, Y$ and $Z$ respectively are $- 349$ , $- 333$ and $- 325$ . Then $X, Y$ and $Z$ respectively are :

Number of short periods in Mendeleev's periodic table is :

Considering the chemical properties, atomic weight of $B e$ was corrected based on:

What is the atomic number of another element present in the same group as the element with $Z = 13$ ?

In a period, elements are arranged strictly in a sequence of:

Classification Of Elements And Periodicity In Properties

Chemistry 8639 Views

In Mendeleev table, the triad of VIII group is :

All elements of the same group will have:

Identify the property which does not reflect the periodicity of the elements.

The low electron affinity value of nitrogen is due to :

Which of the following has zero electron affinity?

The electron affinity values (kJmol−1) of three halogens X, Y and Z respectively are −349, −333 and −325. Then X, Y and Z respectively are :

Number of short periods in Mendeleev's periodic table is :

Considering the chemical properties, atomic weight of Be was corrected based on:

What is the atomic number of another element present in the same group as the element with Z=13?

In a period, elements are arranged strictly in a sequence of:

Chemistry
8639 Views

The electron affinity values (kJmol $^{- 1}$ ) of three halogens $X, Y$ and $Z$ respectively are $- 349$ , $- 333$ and $- 325$ . Then $X, Y$ and $Z$ respectively are :

Considering the chemical properties, atomic weight of $B e$ was corrected based on:

What is the atomic number of another element present in the same group as the element with $Z = 13$ ?