MCQ 1011 Mark
Which of the given elements $\ce{A, B, C, D}$ and $E$ with atomic number $2, 3, 7, 10$ and $30$ respectively belong to the same period?
- A
$\ce{A, B, C}.$
- ✓
$\ce{B, C, D}.$
- C
$\ce{A, D, E}.$
- D
$\ce{B, D, E}.$
AnswerCorrect option: B. $\ce{B, C, D}.$
The elements $\ce{B(Z = 3), C(Z = 7)}$ and $\ce{D(Z = 10)}$ belong to the same period. It is second period.
View full question & answer→MCQ 1021 Mark
The placement of elements in the Newlands' table was compared to :
AnswerThe placement of elements in the Newlands' periodic table was compared to the notes of music where the first note and the eighth note are the same.
Similarly, in Newlands' periodic table, the properties repeat after each interval of $7$ elements.
View full question & answer→MCQ 1031 Mark
Which of the following are the characteristics of isotopes of an element?
- Isotopes of an element have same atomic masses.
- Isotopes of an element have same atomic number.
- Isotopes of an element show same physical properties.
- Isotopes of an element show same chemical properties.
- A
$\ce{(i), (iii)}$ and $\ce{(iv)}.$
- B
$\ce{(ii), (iii)}$ and $\ce{(iv)}.$
- C
$\ce{(ii)}$ and $\ce{(iii)}.$
- ✓
$\ce{(ii)}$ and $\ce{(iv)}.$
AnswerCorrect option: D. $\ce{(ii)}$ and $\ce{(iv)}.$
Isotopes of an element have same atomic number but different atomic masses.
They show same chemical properties but different physical properties.
View full question & answer→MCQ 1041 Mark
What type of oxide would Eka $-$ aluminium form?
AnswerCorrect option: C. $\mathrm{E}_2 \mathrm{O}_3$
Eka $-$ Aluminium $(E)$ forms oxide with the same chemical formula as Aluminium oxide.
Thus, the formula can be represented as $\mathrm{E}_2 \mathrm{O}_3$.
View full question & answer→MCQ 1051 Mark
Which of the following statements about the Modern Periodic Table is correct :
- A
It has $18$ horizontal rows known as Periods.
- B
It has $7$ vertical columns known as Periods.
- ✓
It has $18$ vertical columns known as Groups.
- D
It has $7$ horizontal rows known as Groups.
AnswerCorrect option: C. It has $18$ vertical columns known as Groups.
Modern Periodic Table has $18$ Groups and $7$ periods.
Columns are called groups, while rows are called periods.
View full question & answer→MCQ 1061 Mark
An element $X$ belongs to the $3^{\text {rd }}$ period and $1^{\text {st }}$ group of the periodic table. What is the number of valence electrons in its atom?
AnswerAs the element belongs to the $1^{\text {st }}$ group of the periodic table, so the number of valence electrons in its atom is one.
View full question & answer→MCQ 1071 Mark
The atomic numbers of the elements $\ce{Na, Mg, K}$ and $\ce{Ca}$ are $11, 12, 19$ and $20$ respectively. The element having the largest atomic radius is :
- A
$\ce{Mg}.$
- B
$\ce{Na}.$
- ✓
$\ce{K}.$
- D
$\ce{Ca}.$
AnswerCorrect option: C. $\ce{K}.$
Potassium $(K)$ with an atomic number of $19$ has the largest atomic radius. This is because sodium and potassium are elements of group $1.$ On moving from top to bottom in a group, the atomic radius increases. Magnesium and calcium are elements of group $2.$ The size of the atomic radius decreases on moving from left to right in a period of the periodic table.
View full question & answer→MCQ 1081 Mark
The element with the atomic number $9$ resembles with the element having the atomic number :
AnswerAtomic number $9$ has electronic configuration $= 2, 7$
Atomic number $17$ has an electronic configuration $= 2, 8, 7.$
So, both the elements belong to the same group
i.e. halogens and have similar properties as they have the same number of valence electrons.
View full question & answer→MCQ 1091 Mark
The element which has least tendency to lose electron is :
- A
$\ce{H}$
- B
$\ce{Li}$
- ✓
$\ce{He}$
- D
$\ce{Ne}$
AnswerCorrect option: C. $\ce{He}$
View full question & answer→MCQ 1101 Mark
The element which can from an acidic oxide should be the one whose atomic number is :
AnswerThe element which can form an acidic oxide should be the one with atomic number $16$. Sulphur has an atomic number of $16$ and sulphur oxide is acidic.
View full question & answer→MCQ 1111 Mark
Mendeleev used a Sanskrit numeral before the names of the predicted elements. What was the term used for it?
AnswerA Sanskrit numeral used before the names of the predicted elements was Eka which means one.
View full question & answer→MCQ 1121 Mark
Modern Periodic law is based upon:
MCQ 1131 Mark
Element $X$ forms a chloride with the formula $\mathrm{XCl}_2$, which is a solid with a high melting point. $X$ would most likely be in the same group of the Periodic Table as :
- A
$\ce{Na}$
- ✓
$\ce{Mg}$
- C
$\ce{Al}$
- D
$\ce{Si}.$
AnswerCorrect option: B. $\ce{Mg}$
View full question & answer→MCQ 1141 Mark
The elements A, B, C and D belong to groups 1, 2, 14 and 17 respectively of the periodic table. Which of the following pairs of elements would produce a covalent bond?
MCQ 1151 Mark
An element $X$ belongs to group $2$ and period $3$ of the periodic table. The chemical formulae of its nitrate, sulphate and phosphate respectively will be.
- A
$\mathrm{X}\left(\mathrm{NO}_3\right)_3, \mathrm{X}_2\left(\mathrm{SO}_4\right)_3, \mathrm{X}_2\left(\mathrm{PO}_4\right)_3$
- B
$\mathrm{X}_3\left(\mathrm{NO}_3\right)_2, \mathrm{X}_2\left(\mathrm{SO}_4\right)_2, \mathrm{X}_2\left(\mathrm{PO}_4\right)_3$
- C
$\mathrm{XNO}_3, \mathrm{XSO}_4, \mathrm{XPO}_4$
- ✓
$\mathrm{X}\left(\mathrm{NO}_3\right)_2, \mathrm{XSO}_4, \mathrm{X}_3\left(\mathrm{PO}_4\right)_2$
AnswerCorrect option: D. $\mathrm{X}\left(\mathrm{NO}_3\right)_2, \mathrm{XSO}_4, \mathrm{X}_3\left(\mathrm{PO}_4\right)_2$
Magnesium is the compound. It belongs to the $2^{nd}$ group of the periodic table. The compond it forms with the radicals are $-\mathrm{MgSO}_4$ and $\mathrm{Mg}_3(\mathrm{PO} 4)_2$. With $\mathrm{NO}_3$, it shall form $\mathrm{Mg}\left(\mathrm{NO}_3\right)_2$. All the bonds formed are ionic bonds because $\mathrm{MgSO}_4, \mathrm{Mg}_3(\mathrm{PO} 4)$ and $\mathrm{Mg}\left(\mathrm{NO}_3\right)_2$ is an ionic compound since magnesium is a metal, and $\mathrm{SO}_4$ is considered a non $-$ metal. Covalent compounds occur between two non $-$ metals.
View full question & answer→MCQ 1161 Mark
The properties of eka $-$ aluminium predicted by Mendeleev are the same as the properties of later discovered element :
View full question & answer→MCQ 1171 Mark
Which of the following is correct order of atomic size?
- ✓
$\ce{Na > Mg < Al> Si > PS > Cl}$
- B
$\ce{Na > Mg > AI > Si > P > S > Cl}$
- C
$\ce{Na < Mg < AL < Si < p < S < Cl}$
- D
$\ce{Mg > Na > Al > Si > P > S > Cl}$
AnswerCorrect option: A. $\ce{Na > Mg < Al> Si > PS > Cl}$
The atomic radius of a chemical element is a measure of the size of its atoms, usually the mean or typical distance from the center of the nucleus to the boundary of the surrounding shells of electrons.
View full question & answer→MCQ 1181 Mark
How did Mendeleev predict the existence of some elements yet to be discovered elements in his periodic table?
AnswerProfessor Dmitri Mendeleev published the first periodic table of the atomic elements in 1869 based on properties which appeared with some regularity as he laid out the elements from lightest to heaviest.
When Mendeleev proposed his periodic table, he noted gaps in the table, and predicted that as $-$ of $-$ yet unknown elements existed with properties appropriate to fill those gaps.
View full question & answer→MCQ 1191 Mark
Which of the following statement is correct in regard to the classification of elements?
- A
Elements in modern periodic table are arranged on the basis of increasing atomic masses.
- B
Elements in Mendeleev's periodic table are arranged on the basis of increasing atomic numbers.
- C
In modern periodic table, the element nickel of lower atomic mass is kept before the element cobalt of higher atomic mass.
- ✓
In modern periodic table, the isotopes of chlorine having different atomic masses are kept in the same group.
AnswerCorrect option: D. In modern periodic table, the isotopes of chlorine having different atomic masses are kept in the same group.
The isotopes of chlorine, having different atomic masses but same atomic numbers are kept in the same group in the modern periodic table.
View full question & answer→MCQ 1201 Mark
Which of the following are the correct characteristics of isotopes of an element?
- Same atomic mass.
- Same atomic number.
- Same physical properties.
- Same chemical properties.
- A
$\ce{(i), (ii)}$ and $\ce{(iv)}.$
- B
$\ce{(ii), (iii)}$ and $\ce{(iv)}.$
- C
$\ce{(ii)}$ and $\ce{(iii)}.$
- ✓
$\ce{(ii)}$ and $\ce{(iv)}$.
AnswerCorrect option: D. $\ce{(ii)}$ and $\ce{(iv)}$.
Isotopes of an element have the same atomic number and the same chemical properties.
View full question & answer→MCQ 1211 Mark
Carbon : Non $-$ metal $: :$ Germanium :
AnswerCarbon is a non $-$ metal found in the periodic table.
As for germanium, it is neither a metal nor a non $-$ metal. Instead it is a metalloid.
Carbon : Non $-$ metal $: : $ Germanium : Metalloid
View full question & answer→MCQ 1221 Mark
Which of the following set of elements is written correctly in the order of their increasing metallic character?
- A
$\ce{Mg, Al, Si}.$
- B
$\ce{C, O, N}.$
- C
$\ce{Na, Li, K}.$
- ✓
$\ce{Be, Mg, Ca}.$
AnswerCorrect option: D. $\ce{Be, Mg, Ca}.$
$\ce{Be, Mg}$ and $\ce{Ca}$ are elements of group $2,$ written in order of their increasing metallic character. On moving down in the group, the metallic character increases.
View full question & answer→MCQ 1231 Mark
An element $X$ has mass number $40$ and contains $21$ neutrons in its atom. To which group of the Periodic Table does it belong?
- ✓
Group $1$
- B
Group $4$
- C
Group $2$
- D
Group $3$
AnswerCorrect option: A. Group $1$
View full question & answer→MCQ 1241 Mark
Which has more non $-$ metallic character from the elements $'X\ '$ and $'Y\ ',$ with electronic configurations $2,8,5$ and $2,8,6$ respectively?
AnswerAs we move from left to right across a period, the non $-$ metallic character increases.
Here, $X$ has atomic number $15,$ so, the element is Phosphorous.
$Y$ has atomic number $16,$ so, the element is Sulphur.
As sulphur is present more to the right of the table, so according to the general trend it is more non $-$ metallic.
So, $Y$ has more non $-$ metallic character.
View full question & answer→MCQ 1251 Mark
An element has an atomic number of $15$ with which of the following elements will it show similar chemical properties.
- A
$\ce{Be (4)}$
- B
$\ce{Ne (10)}$
- ✓
$\ce{N (7)}$
- D
$\ce{O (8)}$
AnswerCorrect option: C. $\ce{N (7)}$
View full question & answer→MCQ 1261 Mark
On moving from left to right in a period in the periodic table, the size of the atom.
- A
- ✓
- C
Does not change appreciably.
- D
First decreases and then increases.
AnswerAtomic size decreases along a period. However, the noble gas atom is an exception. It has very large size.
View full question & answer→MCQ 1271 Mark
Which one of the following does not increase while moving down the group of the periodic table?
- A
- B
- ✓
- D
Number of shells in an element.
AnswerElements of the same group have same number of valence electrons hence valency will remain same.
View full question & answer→MCQ 1281 Mark
An element $X$ combines with oxygen to form an oxide $XO.$ This oxide is electrically conducting. Write the formula of the compound formed when $X$ reacts with chlorine.
- A
$\mathrm{XCl}_3$
- B
$\ce{XCl}$
- ✓
$\mathrm{XCl}_2$
- D
$\mathrm{XCl}_5$
AnswerCorrect option: C. $\mathrm{XCl}_2$
View full question & answer→MCQ 1291 Mark
Arrange the following elements in the order of their increasing nonmetallic character $\ce{Li, O, C, Be, F}:$
- A
$\ce{F < O < C < Be < Li.}$
- ✓
$\ce{Li < Be < C < O < F}.$
- C
$\ce{F < O < C < Be < Li.}$
- D
$\ce{F < O < Be < C < Li.}$
AnswerCorrect option: B. $\ce{Li < Be < C < O < F}.$
These all elements belong to same period in which non-metallic characters increases from left to right.
View full question & answer→MCQ 1301 Mark
The term atomic radius refers to?
- A
- ✓
- C
Distance between the centre of nucleus and the first shell.
- D
Size of the outermost orbital.
AnswerThe atomic radius refers to the size of an atom.
It is the distance between the centre of the nucleus and the outermost shell of an atom.
Atomic radius generally decreases on moving left to right across a period and increases down the group.
View full question & answer→MCQ 1311 Mark
What is the atomic number of element of period $3$ and group $17$ of the Periodic Table?
View full question & answer→MCQ 1321 Mark
Which of the following set of elements is written in order of their increasing metallic character?
- ✓
$\ce{Be Mg Ca}.$
- B
$\ce{Na Li K.}$
- C
$\ce{Mg Al Si}.$
- D
$\ce{C O N}.$
AnswerCorrect option: A. $\ce{Be Mg Ca}.$
These elements are in same group but $\ce{Be}$ is at the top, while $\ce{Ca}$ is at bottom. Metallic character increases as we move down the group.
View full question & answer→MCQ 1331 Mark
Identify the element with atomic number $10.$
AnswerAtomic number $10 $ means that atom has $10$ electrons which is neon.
View full question & answer→MCQ 1341 Mark
As we move from left to right in a period in modern periodic table, Atomic sizes of the elements generally :
MCQ 1351 Mark
Which of the following element does not lose an electron easily?
- A
$\ce{Na}.$
- ✓
$\ce{F}.$
- C
$\ce{Mg}.$
- D
$\ce{Al}.$
AnswerCorrect option: B. $\ce{F}.$
$\ce{F}$ is the element that does not lose an electron easily, as it is a non $-$ metal $($halogen$)$ belonging to group $17$ of the periodic table.
View full question & answer→MCQ 1361 Mark
Which of the following elements of noble gases participate in chemical reaction?
- ✓
$\ce{Kr, Rn}$
- B
$\ce{He, Kr}$
- C
$\ce{Rn, He}$
- D
$\ce{He, Ne}$
AnswerCorrect option: A. $\ce{Kr, Rn}$
View full question & answer→MCQ 1371 Mark
An element $X$ combines with hydrogen to form a compound $\mathrm{XH}_3$. The element $X$ is placed on the right side of the periodic table. Which of the following statement is correct for element $X\ ?$
- Has two valence electrons.
- Is a metal and is solid.
- Is a non $-$ metal and is a gas.
- Has five valence electrons.
- $\mathrm{XH}_3$ reacts with water to forma basic compound.
- A
$\ce{I, H}$ and $\ce{III}$
- B
$\ce{II, III}$ and $\ce{IV}$
- ✓
$\ce{III, IV}$ and $\ce{V}$
- D
$\ce{V, I}$ and $\ce{II}$
AnswerCorrect option: C. $\ce{III, IV}$ and $\ce{V}$
The element $X$ is nitrogen which reacts with hydrogen to form $\mathrm{NH}_3$.
View full question & answer→MCQ 1381 Mark
Which of the following will have the most negative electron affinity and which one has the least?
- A
$\ce{F, CI}$
- B
$\ce{CI, F}$
- ✓
$\ce{CI, P}$
- D
$\ce{CI, S}$
AnswerCorrect option: C. $\ce{CI, P}$
$\ce{CI}$ have the most negative electron affinity and $\ce{P}$ which one has the least.
View full question & answer→MCQ 1391 Mark
The elements $\ce{A, B, C, D}$ and $E$ have atomic numbers $9, 11, 17, 12$ and $13$ respectively. The pair of elements which belongs to the same group of the periodic table is:
- A
$A$ and $B$.
- B
$B$ and $D.$
- ✓
$A$ and $C.$
- D
$D$ and $E.$
AnswerCorrect option: C. $A$ and $C.$
Electronic configuration of $A\ (9):$
$\begin{matrix}\text{K} \ \ \text{L}\\2\ \ \ 7\end{matrix}$
Electronic configuration of $C \ (17):$
$\begin{matrix}\text{K}\ \ \text{L}\ \ \text{M}\\2\ \ \ 8\ \ \ 7\end{matrix}$
Group number of $A$ and $B =$ valence electron $+\ 10$
$= 7 + 10 = 17.$
View full question & answer→MCQ 1401 Mark
An element $X$ forms an oxide $\mathrm{X}_2 \mathrm{O}_3$. In which group of Mendeleev's periodic table is this element placed?
- A
Group $\ce{II}.$
- ✓
Group $\ce{III}.$
- C
Group $\ce{V}.$
- D
Group $\ce{VIII}.$
AnswerCorrect option: B. Group $\ce{III}.$
The element which forms the oxide $\mathrm{X}_2 \mathrm{O}_3$ is placed in group $3$ of the periodic table.
View full question & answer→MCQ 1411 Mark
Which of the following is the outermost shell for elements of period $2\ ?$
- A
$K $ shell.
- ✓
$L$ shell.
- C
$M$ shell.
- D
$N$ shell.
AnswerCorrect option: B. $L$ shell.
The elements of $2^{\text {nd }}$ period contain two shells; $K$ and $ L $ shell.
View full question & answer→MCQ 1421 Mark
Which of the following elements has the maximum number of outermost electrons?
- A
$\ce{Na}$
- B
$\ce{Mg}$
- C
$\ce{Si}$
- ✓
$\ce{P}$
AnswerCorrect option: D. $\ce{P}$
Sodium has $1$ electron, magnesium has $2$ electrons, silicon has $4$ electrons, and phosphorous has $5$ electrons in its outermost shell.
Therefore, phosphorous has the maximum number of electrons in its outermost shell.
View full question & answer→MCQ 1431 Mark
In Mendeleev's periodic table, gaps were left for the elements to be discovered later on. An element which found a vacant place in the periodic table later on is:
- A
$\ce{Be}.$
- B
$\ce{Si}.$
- ✓
$\ce{Ge}.$
- D
$\ce{Se}.$
AnswerCorrect option: C. $\ce{Ge}.$
Germanium $($eka $-$ silicon$)$ is the element which found a vacant place in the periodic table later on.
View full question & answer→MCQ 1441 Mark
Which of the following element would lose an electron easily?
- A
$\ce{Mg}.$
- B
$\ce{Na}.$
- ✓
$\ce{K.}$
- D
$\ce{Ca}.$
AnswerCorrect option: C. $\ce{K.}$
$\ce{K}$ would lose an electron easily as it is a group $1$ metal whose atomic number is greater than that of $\ce{Na},$ which also belongs to group $1. \ce{Mg}$ and $\ce{Ca}$ are group $2$ metals and the tendency to lose electrons decreases on moving from left to right in a period of periodic table.
View full question & answer→MCQ 1451 Mark
Which of the following forms the basis of the modern periodic table?
AnswerModern periodic table is based on the atomic numbers of elements as according to the modern periodic law the properties of elements are a periodic function of their atomic numbers.
View full question & answer→MCQ 1461 Mark
Arrange the following elements in the order of the decreasing metallic character $\ce{Na, Si, Cl, Mg, Al}:$
- A
$\ce{Cl > Si > Al > Mg > Na}$
- ✓
$\ce{Na > Mg > Al > Si > CI}$
- C
$\ce{Na > Al > Mg > CI > Si}$
- D
$\ce{Al > Na > Si > Ca > Mg}$
AnswerCorrect option: B. $\ce{Na > Mg > Al > Si > CI}$
As we move from left to right in periodic table, metallic characters decreases and non $-$ metallic characters increases.
Here $\ce{Na, Si, Cl, Mg, Al}$ belong to same period so we have to check their position in period.
View full question & answer→MCQ 1471 Mark
Which of the following has correct order to gain electron?
- A
$\ce{C < N < O < F}$
- ✓
$\ce{F < O < N < C}$
- C
$\ce{O < F < N < C}$
- D
$\ce{O < C < N < F}$
AnswerCorrect option: B. $\ce{F < O < N < C}$
Order to gain electron $\ce{F < O < N < C}$
View full question & answer→MCQ 1481 Mark
Which one of the following does not increase while moving down the group of the periodic table?
AnswerThe number of valence electrons does not increase while moving down the group in the periodic table.
View full question & answer→MCQ 1491 Mark
Which of the following elements will form an acidic oxide?
- ✓
An element with atomic number $7$.
- B
An element with atomic number $3.$
- C
An element with atomic number $12.$
- D
An element with atomic number $19.$
AnswerCorrect option: A. An element with atomic number $7$.
Formation of acidic oxides is character of non $-$ metals. Here element with atomic number $7$ is a non $-$ metal that is nitrogen. Rests of all are metals.
View full question & answer→MCQ 1501 Mark
What is the valency of magnesium with atomic number $12\ ?$
AnswerThe electronic configuration of magnesium is $2, 8, 2.$
The valence shell contains $2$ electrons.
Therefore the valency is two.
View full question & answer→