MCQ 11 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Increasing order of non $-$ metallic character is $: \ce{Si < B < C < N < F}.$
Reason : Non $-$ metallic character increases along a period and decreases down the group.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
$\begin{matrix}\text{Period/Group} & 13 &14 & 15 & 16 & 17\\ 2 &\text{B}&\text{C} &\text{N}& - &\text{F}\\3 & -&\text{Si}&- & -&-\end{matrix}$
As non $-$ metallic character increases along a period and decreases down a group, $\ce{Si}$ is the least non $-$ metallic element and non $-$ metallic character increases from $B$ to $C$ to $N$ to $F.$ Hence, increasing order of non $-$ metallic character is $: \ce{Si < B < C < N < E}.$
View full question & answer→MCQ 21 Mark
In each of the following questions, a statement of Assertion is given by the corresponding statement of Reason. Of the statements, mark the correct answer as. Sodium is an element of group $1$ of the modern periodic table.
All the elements of group $1$ of the modern periodic table contain two electrons in their outermost shell.
- A
Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
- B
Both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
- ✓
Assertion is true, but Reason is false.
- D
Assertion is false, but Reason is true.
AnswerCorrect option: C. Assertion is true, but Reason is false.
In general, the number of valence electrons is the same within a column and increases from left to right within a row. Group $1$ elements have just one valence electron and group $18$ elements have eight, except for helium, which has only two electrons total.
View full question & answer→MCQ 31 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below:
Assertion : Decreasing order of atomic radii is $: \ce{Cl > F > 0 > S}$.
Reason : Atomic radius increases as the number of energy level increases and decreases as nuclear charge increases.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- ✓
$A$ is false, but $R$ is true.
AnswerCorrect option: D. $A$ is false, but $R$ is true.
Correct order is $\ce{S > Cl > O > F.}$
View full question & answer→MCQ 41 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : According to Mendeleev's periodic law, the properties of elements is the periodic function of their atomic numbers.
Reason : Mendeleev placed some elements with higher atomic mass before the elements with lower atomic mass.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- ✓
$A$ is false, but $R$ is true.
AnswerCorrect option: D. $A$ is false, but $R$ is true.
According to Mendeleev's periodic law, the properties of elements are the periodic function of their atomic masses.
View full question & answer→MCQ 51 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Atomic size of potassium is greater than that of sodium.
Reason : As we go down the group, atomic radius increases.
- ✓
Both $A$ and $R $ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R $ are true, and $R$ is correct explanation of the assertion.
View full question & answer→MCQ 61 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Group $18$ is placed at the extreme right of the periodic table.
Reason : lt is in accordance with their electronic configuration.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
View full question & answer→MCQ 71 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Alkali metals do not form dipositive ions.
Reason : After loss of one electron, alkali metals achieve stable configuration of noble gas.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
View full question & answer→MCQ 81 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : $\ce{Li}$ and $\ce{Mg}$ are elements of second period.
Reason : Both are metals.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- ✓
$A$ is false, but $R$ is true.
AnswerCorrect option: D. $A$ is false, but $R$ is true.
Lithium belongs to second period whereas magnesium belongs to third period and both are metals.
View full question & answer→MCQ 91 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Increasing order of metallic character is $: : \ce{P < Si < Be < Mg < Na}$
Reason : Metallic character increases along a period and decreases down a group.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- ✓
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: C. $A$ is true, but $R$ is false.
Elements can be arranged in different periods and groups as follows :
$\begin{matrix}\text{Period/ Group} & 1 & 2 & 13 &14&15\\2\text{nd}&-&\text{Be}&-&-&-\\3\text{rd}&\text{Na}&\text{Mg}&-&\text{Si}&\text{P}\end{matrix}$
As metallic character decreases along a period and increases down a group, so $\ce{Na}$ is the most metallic
element and $P$ is the least metallic element and among $\ce{Be}$ and $\ce{Mg, Mg}$ is more metallic. Hence, increasing order of metallic character is : $\ce{P < Si < Be < Mg < Na}.$
View full question & answer→MCQ 101 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Atomic radius in general decreases along a period.
Reason : In a period, effective nuclear charge decreases.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- ✓
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: C. $A$ is true, but $R$ is false.
Effective nuclear charge increases along a period.
View full question & answer→MCQ 111 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Chlorine is the most electronegative element of the halogen family.
Reason : Size of chlorine is more than that of fluorine.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- ✓
$A$ is false, but $R$ is true.
AnswerCorrect option: D. $A$ is false, but $R$ is true.
Fluorine is most electronegative element of the halogen family.
View full question & answer→MCQ 121 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Elements in the same vertical column have similar properties.
Reason : Periodic properties of elements is a function of atomic number.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
Elements in the same vertical column $($group$)$ have similar properties due to similar outer electronic configurations.
View full question & answer→MCQ 131 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Down the group, atomic radius increases.
Reason : Electrons are added in new shell.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
New shells are added down the group, hence, atomic radius increases.
View full question & answer→MCQ 141 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : ln Dobereiner's triad, the three elements present, have same gaps of atomic numbers.
Reason : Elements in a triad have similar properties.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- ✓
$A$ is false, but $R$ is true.
AnswerCorrect option: D. $A$ is false, but $R$ is true.
In Dobereiner's triad, the atomic mass of the middle element was roughly the average of the atomic masses of other two elements.
View full question & answer→MCQ 151 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion: ln Newlands' octaves, the properties of lithium and sodium were found to be same.
Reason : Sodium is the eighth element after lithium.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
View full question & answer→MCQ 161 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Atomic size of As is more than that of $P.$
Reason : Atomic size decreases along a period.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
Atomic size increases down a group.
View full question & answer→MCQ 171 Mark
In each of the following questions, a statement of Assertion is given by the corresponding statement of Reason. Of the statements, mark the correct answer as. Atomic size increases on going down the group in the modern periodic table.
New shells are being added as we go down the group in the modern periodic table.
- ✓
Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
- B
Both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
- C
Assertion is true, but Reason is false.
- D
Assertion is false, but Reason is true.
AnswerCorrect option: A. Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
Moving down a group in the periodic table, the number of filled electron shells increases. In a group, the valence electrons keep the same effective nuclear charge, but now the orbitals are farther from the nucleus. $........$ Therefore, the positive nucleus pulls the electrons tighter and the radius is smaller
View full question & answer→MCQ 181 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Argon $($at. mass $39.94)$ has been placed before potassium $($at. mass $39.10)$ in the periodic table.
Reason : ln modern periodic table, elements have been placed in order of their increasing atomic numbers.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
View full question & answer→MCQ 191 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Nobel elements were not included in Mendeleev's periodic table.
Reason : Mendeleev arranged the then known elements in order of their increasing atomic mass.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
The noble gases were not known at Mendeleev's time.
View full question & answer→MCQ 201 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Atomic mass of certain elements are expressed in fraction, taking in account the availability of its various isotopes.
Reason : Isotopes of an element have the same atomic mass but different atomic number.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- ✓
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: C. $A$ is true, but $R$ is false.
Isotopes have same atomic number but different atomic mass.
View full question & answer→MCQ 211 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Number of valence electrons decreases down the group.
Reason : Number of valence electrons increases when we move left to right in a period.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- ✓
$A$ is false, but $R$ is true.
AnswerCorrect option: D. $A$ is false, but $R$ is true.
Number of valence electrons remains same in a group.
View full question & answer→MCQ 221 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : The group $18$ consists of elements which are in gaseous state under ordinary conditions.
Reason : All the elements of group $18$ have stable configuration.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
Noble gases have stable configuration and they are gases at room temperature.
View full question & answer→