Shielding Effect

Q.

What is the shielding effect in chemistry?

Q. Why the atomic radii of the second and third transition series are almost same?

1. Actinoid contraction
2. Radioactive nature
3. Lanthanoid contraction
4. Filled d-orbital

Q. Screening effect is not observed in :-

1. $H{e}^{+}$
2. $L{i}^{2+}$
3. $B{e}^{3+}$
4. In all cases

Q.

The screening effect of inner shells decreases the effective nuclear charge. The order of screening effect of subshells is s>p>d>f.

With respect to the above facts, predict the gradation of atomic size in lanthanide elements?

Q. Which element among the Lanthanides has the smallest atomic radius?

1. Cerium
2. Lutetium
3. Europium
4. Gadolinium

Q. How the greater electronic charge density affects the more attractions of electrons in the electronegative atoms??🤔🤔🤔
​​​​​If there is a greater electronic charge density, then , it must be satisfied with the electrons, and thus the attractions will decrease. But Sir said, greater electronic charge density leads to have a tendency to attract more electrons in the electronegative atoms.

Why does this happen???🤔🤔🤔
And what is the actual explanation??

Q. The atomic sizes of $Ga$ and $Al$ are almost same because

1. Poor shielding effect of the electrons in $d$ orbitals, effective nuclear charge increases in gallium.

2. More shielding effect of $d$ electrons

3. Poor shielding effect of $f$ orbitals in gallium

4. High screening effect of $3s,3pand3d$ electrons.

Q. The $E_{M^{3+}/M^{2+}}^0$ value of Scandium is expected to be

1. highly negative
2. zero
3. less positive
4. highly positive

Q.

The atomic sizes of $Ga$ and $Al$ are almost the same because:

1. More shielding effect of $d$ electrons
2. Poor shielding effect of the electrons in $d$ orbitals

3. Poor shielding effect of $f$ orbitals in gallium

4. High screening effect of $3s,3pand3d$ electrons.

Q. The maximum number of unpaired electrons present in px orbital is?

Q.

The given table shows the elements with the same number of electrons in its valence shell.

Elements	$A$	$B$	$C$
M.P.	$63.0$	$180.0$	$97.0$

State:

(ii) Arrange them in order of increasing metallic character.

Q. The effective nuclear charge for $4s$ electrons of $Zn$ will be

1. 26.85
2. 4.35
3. 10
4. 15.3

Q. Screening effect is not observed in:

1. $L{i}^{2+}$
2. $B{e}^{3+}$
3. all of the above
4. $H{e}^{+}$

Q. The lanthanoid contraction is responsible for the fact that-

1. $Zr$ and $Y$ have about the same radius
2. $Zr$ and $Nb$ have simillar oxidation state
3. $Zr$ and $Hf$ have about the same radius
4. $Zr$ and $Zn$ have simillar oxidation state

Q.

How many lone pairs of electrons are there in the tri iodide ion ?

Q. For a p - block element, its 3d, 3s, 3p and 4s orbitals are completely filled and the differentiating electron goes to the 4p orbital. The element should have its atomic number in the range

1. 13 - 18
2. 21 - 26
3. 31 - 36
4. 49 - 54

Q. Calculate the $Z_{\text{eff}}$ on the electron present in $5d-$ orbital of $Gd$ (Atomic number $=64$).

Q. For $Cu$, effective nuclear charge felt by a $4s$-electron is:

1. $2.95$
2. $1.65$
3. $1.0$
4. $2.2$

Q.

In a given shell, the order of screening effect is?

1. 

2. 

3. 

4. 

5. 

Q. The effective nuclear charge for $4s$ electrons of $Zn$ will be

1. 26.85
2. 4.35
3. 15.3
4. 10

Q.

Among the following species, how many have their ionic size greater than $O^{2-}$?___

$S{e}^{2-},F^{-},N^{3-},P^{3-}$

Q. Which is correct information for bond parameters?

1. Bond length is defined as the distance between the nuclei of two bonded atoms in a molecule
2. Bond angle is the angle between two adjacent bonds of an atom in a molecule
3. Bond order is the number of bonds between the two atoms in a molecule
4. All of these

Q. What is the trend of screening effect along period

Q.

Select the correct relation.

1. $I.E{.}_1\left(Cu\right)<I.E{.}_1\left(Zn\right)butI.E{.}_2\left(Cu\right)>I.E{.}_2\left(Zn\right)$

2. $I.E{.}_1\left(Cu\right)<I.E{.}_1\left(Zn\right)andI.E{.}_2\left(Cu\right)<I.E{.}_2\left(Zn\right)$

3. $I.E{.}_1\left(Cu\right)>I.E{.}_1\left(Zn\right)andI.E{.}_2\left(Cu\right)>I.E{.}_2\left(Zn\right)$

4. $I.E{.}_1\left(Cu\right)>I.E{.}_1\left(Zn\right)andI.E{.}_2\left(Cu\right)>I.E{.}_2\left(Zn\right)$

Q. The screening effect of $d-$electrons is:

1. Equal to $p-$ electrons
2. Much more than $p-$ electrons
3. Same as $f-$ electrons
4. Less than $p-$ electrons

Q.

The atomic radius increases as we go along a period

1. True

2. False

Q. A p-orbital can accommodate upto what number of electrons and why?

Q. The calculated spin only magnetic moment of $C{r}^{2+}$ ion is :

1. 4.90 BM
2. 5.92 BM
3. 3.87 BM
4. 2.84 BM

Q. Is there anything like Valence Electron configuration and if it is so what is the difference between the normal Electronic Configuration and The Valence Electron configuration?

Q. Screening effect is not observed in :-

1. $H{e}^{+}$
2. $L{i}^{2+}$
3. $B{e}^{3+}$
4. In all cases