Trend in Atomic Radius

Q. According to $EAN$ rule, how many $CO$ groups should be attached to $Fe$?

1. $4$
2. $5$
3. $6$
4. $8$

Q. Which of the following ore is best concentrated by froth - flotation process?

1. Cassiterite
2. Magnetite
3. Malachite
4. Galena

Q.

Give Reasons:

What is the cause of Lanthanide Contraction?

Q. Which one of the following ions has the highest value of ionic radius?

1. $L{i}^{+}$
2. $O^{2-}$
3. $B^{3+}$
4. $F^{-}$

Q. A transition metal $M$ can exist in two oxidation states $+2$ and $+3$. It forms an oxide whose experimental formula is given by $M_{x}O$, where x < 1. Then the ratio of metal ions in $+3$ state to those in $+2$ state in terms of x is given by:

1. $(1-x)/(1+x)$
2. 1 + 2x
3. $1+\frac{x}{2}$
4. $\frac{2(1-x)}{3x-2}$

Q.

Consider the hypothetical situation where the azimuthal quantum number, $\mathrm{l}$, takes values $0$, $1$, $2$, ...... $n+1$, where $\mathrm{n}$ is the principal quantum number. Then, the element with atomic number:

1. $13$ has a half-filled valence subshell.

2. $9$ is the first alkali metal.

3. $8$ is the first noble gas.

4. $6$ has a $2p$- valence subshell.

Q. Which is the correct electronic configuration of the element Mendelevium (Md)?

1. $\left[Rn\right]5f^{14}7s^1$
2. $\left[Rn\right]5f^{13}6d^{1}7s^1$
3. $\left[Rn\right]5f^{13}6d^{0}7s^2$
4. $\left[Rn\right]5f^{13}6d^{0}7s^2$

Q. The correct order of ionic radii for the ions, $P^{3-},S^{2-},C{a}^{2+},K^{+},C{l}^{-}$ is

1. $K^{+}>C{a}^{2+}>P^{3-}>S^{2-}>C{l}^{-}$
2. $P^{3-}>S^{2-}>C{l}^{-}>C{a}^{2+}>K^{+}$
3. $P^{3-}>S^{2-}>C{l}^{-}>K^{+}>C{a}^{2+}$
4. $C{l}^{-}>S^{2-}>P^{3-}>C{a}^{2+}>K^{+}$

Q.

How many Groups are in the Periodic Table?

Q.

257. Ionization energy decreases down the group due to

1. increase in charge

2. increase in atomic size

3. decrease in size

4. decreasing in shielding effect

Q. Match List-I with List-II.

List-I (Electronic configuration of elements )	List-II (I.E. in kJ/mol)
(a) $1s^{2}2s^2$	(i) 801
(b) $1s^{2}2s^{2}2p^4$	(ii) 899
(c) $1s^{2}2s^{2}2p^3$	(iii) 1314
(d) $1s^{2}2s^{2}2p^1$	(iv) 1402

1. (a) – (ii), (b) – (iii), (c) – (iv), (d) – (i)
2. (a) – (iv), (b) – (i), (c) – (ii), (d) – (iii)
3. (a) – (i), (b) – (iv), (c) – (iii), (d) – (ii)
4. (a) – (i), (b) – (iii), (c) – (iv), (d) – (ii)

Q.

How does atomic radius vary in a period and in a group? How do you explain the variation?

Q. Number of sodium atom present in $8\text{g}$ of sodium is $X\times {10}^{23}$, then the value of $X$ is:
[Take $N_A=6\times {10}^{23}$]

1. $2.08$
2. $0.8$
3. $4.08$
4. $3.80$

Q.

What is the key difference between lanthanoid contraction and actinoid contraction?

Q. The correct sequence which shows decreasing order of the ionic radii of the elements is :

1. $A{l}^{3+}>M{g}^{2+}>N{a}^{+}>F^{-}>O^{2-}$
2. $N{a}^{+}>F^{-}>M{g}^{2+}>O^{2-}>A{l}^{3+}$
3. $N{a}^{+}>M{g}^{2+}>A{l}^{3+}>O^{2-}>F^{-}$
4. $O^{2-}>F^{-}>N{a}^{+}>M{g}^{2+}>A{l}^{3+}$

Q.

How would you explain the lower atomic radius of Ga as compared to Al?

Q.

For $1\mathrm{molal}$ aqueous solution of the following compounds, which one will show the highest freezing point?

1. $\left[\mathrm{Co}{\left({\mathrm{H}}_2\mathrm{O}\right)}_5\mathrm{Cl}\right]{\mathrm{Cl}}_2.{\mathrm{H}}_2\mathrm{O}$

2. $\left[\mathrm{Co}{\left({\mathrm{H}}_2\mathrm{O}\right)}_4{\mathrm{Cl}}_2\right]\mathrm{Cl}.2{\mathrm{H}}_2\mathrm{O}$

3. $\left[\mathrm{Co}{\left({\mathrm{H}}_2\mathrm{O}\right)}_3{\mathrm{Cl}}_3\right].3{\mathrm{H}}_2\mathrm{O}$

4. $\left[\mathrm{Co}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]{\mathrm{Cl}}_3$

Q.

The first ionization energy of magnesium is smaller as a compound to that of elements X and Y but higher than that of Z. The elements X, Y, and Z, respectively are:

1. Argon, Lithium, and Sodium

2. Chlorine, Lithium, and Sodium

3. Neon, Sodium, and Chlorine

4. Argon, Chlorine, and Sodium

Q. Why is there an increase in the atomic radius of transition elements at the end of the period?

1. Increased electron-electron repulsions
2. Decreased electron-electron repulsions
3. Increase in nuclear charge
4. Increase in atomic mass

Q. The ionic radii of $F^{-}$ and $O^{2-}$ respectively are $1.33\stackrel{\circ }{A}$ and $1.4\stackrel{\circ }{A}$ while the covalent radius of $N$ is $0.74\stackrel{\circ }{A}$.

The correct statement for the ionic radius of $N^{3-}$ from the following is :

1. It is smaller than $O^{2-}$ and $F^{-}$ , but bigger than of $N$
2. It is bigger than $F^{-}$ and $N$, but smaller than of $O^{2-}$
3. It is bigger than $O^{2-}$ and $F^{-}$
4. It is smaller than $F^{-}$ and $N$

Q. Which of the following species are isoelectronic?

$i\left)Neii\right)O^{2-}iii\left)M{g}^{2+}iv\right)F$

$v\left)A{l}^{3+}vi\right)C{l}^{-}vii\left)Kviii\right)Na$

1. $Ne,O^{2-},M{g}^{2+},A{l}^{3+}$
2. $C{l}^{-},O^{2-},F,A{l}^{3+}$
3. $A{l}^{3+},C{l}^{-},M{g}^{2+},O^{2-}$
4. $Na,M{g}^{2+},C{l}^{-},Ne$

Q. Actinoid contraction is greater than lanthanoid contraction because the shielding effect of 5f orbitals is poorer than that of 4f orbitals, then why is the ionisation enthalpies of actinoids less than that of the lanthanoids?

Q.

The atomic radii of the first group elements are given below : [Group-I element - Atomic Radii (pm)] $\mathrm{Na}-86,\mathrm{K}-231,\mathrm{Rb}-244,\mathrm{Cs}-282$. State the reason behind the observed trend in the above elements.

Q.

Amongst the following, select the element with highest ionisation enthalpy

1. Sodium

2. Potassium

3. Beryllium

4. Magnesium

Q.

Dipole moment of the hydrides of group 15 elements decreases in the order:

1. AsH₃ , BiH₃ , SbH₃ , NH₃ , PH₃
2. BiH₃ , SbH₃ , AsH₃ , PH₃ , NH₃
3. NH₃ , PH₃ , AsH₃ , BiH₃ , SbH₃
4. PH₃ , NH₃ , AsH₃ , SbH₃ , BiH₃

Q. Arrange the following in order of increasing radii:
(b) $M{g}^{2+},Mg,M{g}^{+}$

Q. $B$ has a smaller first ionization enthalpy than $Be$. Consider the following statements:

(i) it is easier to remove $2p$ electron than $2s$ electron
(ii) $2p$ electron of $B$ is more shielded from the nucleus by the inner core of electrons than the $2s$ electrons of $Be$
(iii) $2s$ electron has more penetration power than $2p$ electron
(iv) atomic radius of $B$ is more than $Be$
(atomic number $B=5,Be=4$)
The correct statements are :

1. $\left(i\right),\left(iii\right)$ and $\left(iv\right)$
2. $\left(i\right),\left(ii\right)$ and $\left(iii\right)$
3. $\left(i\right),\left(ii\right)$ and $\left(iv\right)$
4. $\left(ii\right),\left(iii\right)$ and $\left(iv\right)$

Q.

Which energy state of doubly ionized lithium has same energy as that of first excitation state of hydrogen? (given $\mathrm{z}$ for lithium $=3$)

Q.

Which of the following order of radii is correct?

1. 

2. 

3. 

4. 

Q.

Among the elements Ca, Mg, P and Cl there order of increasing atomic radii is

1. Mg < Ca < Cl < P

2. Cl < P < Mg < Ca
   

3. P < Cl < Ca < Mg
   

4. Ca < Mg < P < Cl