Atomic Radius

Q.

What is meant by size of an atom and on what factors does it depend? Discuss its variation in the Periodic Table.

Q. The ratio of radii of first orbit of $H$, $H{e}^{+}$ and $L{i}^{2+}$ is:

1. 1 : 2 : 3
2. 6 : 3 : 2
3. 1 : 4 : 9
4. 9 : 4 : 1

Q. The correct order of atomic radii for the following isoelectronic species $F^{-},O^{2-},N{a}^{+},M{g}^{2+}$ is:

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

Q. In comparison to the parent atom, the size of the positive ion is:

1. 
   Smaller
2. 
   Normal
3. 
   Equal
4. 
   Greater

Q. The effective nuclear charge across the period (from left to right)

1. Increases
2. Decreases
3. First increases and then decreases
4. First decreases and then increases

Q. Among the following compounds, which has the maximum lattice energy?

1. $KBr$
2. $NaCl$
3. $NaF$
4. $LiF$

Q.

The Van der Waals radii of $O,N,Cl,F$ and $Ne$ increases in the order?

1. $N,F,O,Ne,Cl$

2. $N,O,F,Ne,Cl$

3. $F,O,Ne,N,Cl$

4. $F,Cl,O,N,Ne$

Q.

How does the atomic size vary in going from $Na$ to $Cl$ in the periodic table?

Q. Which of the following is the correct order of the atomic size of C, N, P and S?

1. $\text{N < C < S < P}$
2. $\text{N < C < P < S}$
3. $\text{C < N < S < P}$
4. $\text{C < N < P < S}$

Q. van der waals radius is:

1. Twice the bond length
2. Half the bond length
3. Half the distance between centres of nuclei of two non bonded atoms of adjacent molecules in solid state
4. Equal to covalent radius

Q. Arrange the following alkali metals in the increasing order of their metallic nature:

1. $Rb$
2. $K$
3. $Na$
4. $Cs$
5. $Li$

Q. The percentage packing efficiency of the two dimensional hcp arrangement of sphere for unit cell ABCDEF shown below is:

1. 74.05%
2. 68.02%
3. 90.64%
4. 78.54%

Q. The radial distribution functions $\left[P\right(r\left)\right]$ is used to determine the most probable radius, which is used to find the electron in a given orbital $\frac{dP\left(r\right)}{dr}$ for 1s-orbital of hydrogen like atom having atomic number $Z$, is $\frac{dP}{dr}=\frac{4Z^3}{a_0^3}(2r-\frac{2Z{r}^2}{a_0})e^{\frac{-2Zr}{a_0}}$. Which of the following statements is/are correct?

1. At the maximum value of the radial distribution function $\frac{dP\left(r\right)}{dr}=0$, one antinode is present
2. Most probable radius of $L{i}^{2+}$ is $\frac{a_0}{2}\text{pm}$
3. Most probable radius of $H{e}^{+}$ is $\frac{a_0}{2}\text{pm}$
4. Most probable radius of hydrogen atom is $a_0\text{pm}$

Q. The correct order of increasing ionic radius for $F^{-},N{a}^{+},S^{2-},C{l}^{-}$ and $K^{+}$ is:

1. $F^{-}<N{a}^{+}<S^{2-}\approx C{l}^{-}<K^{+}$
2. $N{a}^{+}<K^{+}<F^{-}<C{l}^{-}\approx S^{2-}$
3. $N{a}^{+}<F^{-}\approx K^{+}<C{l}^{-}<S^{2-}$
4. $N{a}^{+}\approx F^{-}<C{l}^{-}<S^{2-}<K^{+}$

Q. Predict the behaviour of both oxides $N{a}_{2}O$ and $C{l}_2{O}_7$

1. Both are acidic oxides
2. Both are basic oxides
3. $N{a}_{2}O$ is acidic and $C{l}_2{O}_7$ is basic oxide
4. $N{a}_{2}O$ is basic and $C{l}_2{O}_7$ is acidic oxide

Q. In which of the following pairs, the difference between the covalent radii of two metals is maximum?

1. $K,Ca$
2. $Mn,Fe$
3. $Co,Ni$
4. $Cr,Mn$

Q. Among the following species, which has the maximum hydration energy?

1. $O{H}^{-}$
2. $N{H}_4^{+}$
3. $F^{-}$
4. $H^{+}$

Q. Packing fraction in a hexagonal arrangement is:

1. $\frac{\pi }{3\sqrt{2}}$
2. $\frac{\pi }{3\sqrt{3}}$
3. $\frac{\pi }{2\sqrt{3}}$
4. $\frac{\pi }{6}$

Q. The correct decreasing order of atomic size of the following species is:
$K^{+},C{l}^{-},S^{2-},C{a}^{2+}$

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

Q. Among the following oxides, which has the maximum lattice energy?

1. $MgO$
2. $CaO$
3. $SrO$
4. $BaO$

Q. The correct decreasing order of atomic size of the following species is:
$K^{+},C{l}^{-},S^{2-},C{a}^{2+}$

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

Q. Identify the correct order of acidic strengths of $C{O}_2,CuO,CaO\text{and}{H}_{2}O$

1. $CaO<CuO<H_{2}O<C{O}_2$
2. $H_{2}O<CuO<CaO<C{O}_2$
3. $CaO<H_{2}O<CuO<C{O}_2$
4. $H_{2}O<C{O}_2<CaO<CuO$

Q. A trend common to both group I and VII elements in the periodic table as atomic number increases is :

1. atomic radius increases
2. oxidising power increases
3. reactivity with water increases
4. None of the above

Q. Find the correct order of the ionic radius of following isoelectronic species.

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

Q. The atomic radii of fluorine and neon in Angstrom units are respectively given by

1. $1.60,1.60$
2. None of the above
3. $0.72,0.72$
4. $0.72,1.60$