Which of the following statements is correct for an element that forms oxides in different oxidation states?

 

1.	The oxide is neutral when the element is in its highest oxidation state.
2.	The oxide is most acidic when the element is in its highest oxidation state.
3.	The oxide is amphoteric when the element is in its highest oxidation state.
4.	The oxide is most basic when the element is in its highest oxidation state.

Assertion: The $5^{th}$ period of the periodic table contains 18 elements and not 32.

Reason: When n = 5, the value of l = 0, 1, 2, 3. The order in which the energy of available orbits 4d, 5s and 5p increases is 5s < 4d < 5p, and the total number of orbitals available is 9, thus 18 electrons can be accommodated.

Assertion : :The 4f- and 5f- inner transition series of elements are placed separately at
the bottom of the periodic table.

Reason : (i) This prevents the undue expansion of the periodic table i.e., maintains its structure.
(ii) This preserve the principle of classification by keeping elements with similar properties in a single column.

Assertion : Manganese (atomic number 25 ) has a less favourable electron affinity than its neighbours on either side because.

Reason : The Manganese has stable, ${\left[Ar\right]}^{18}3d^{5}4s^2$ electrons configuration.

The correct order among the following options is: 

1. F > N > C > Si > Ga - Non-metallic character.

2. F > Cl > O >N - Oxidising property.

3. C < Si > P > N  - Electron affinity value.

4. All of the above.

Which of the following statements is not correct?

(1) The first ionization energies (in KJ $mo{l}^{-1}$) of carbon, silicon, germanium, tin, and lead are 1086, 786, 761, 708 and 715 respectively.

(2) Down the group, electronegativity decreases from B to Tl in boron family.

(3) Among oxides of the elements of carbon family, CO is neutral, GeO is acidic and SnO is amphoteric.

(4) The 4f- and 5f- inner transition elements are placed separately at the bottom of the periodic table to maintain its structure.

Which of the following statements are correct ?

1. (i), (iii) and (iv)                     
2. (ii), (iii) and (iv)
3. (i), (ii) and (iv)                         
4. (i), (ii) and (iii)  

The electron gain enthalpies of halogens in kJ mol^-1 are given below.

F =-332, Cl =-349, Br =-325, I =-295.

The lesser negative value for F as compared to that of Cl is due to:
 

1. Strong electron-electron repulsions in the compact 2p-subshell of F.

2. Weak electron-electron repulsions in the bigger 3p-subshell of Cl.

3. Smaller electronegativity value of F than Cl.

4. 1 & 2 both 

Which of the following orders are correct for the ionization energies?

(A) \(  B a   <   S r   <   C a        \)                  
(B) \(S^{2 -} < S   < S^{2 +}\)
(C) \(C   <   O < N\)
(D) \(M g   <   A l   <   S i\)

1. A, B and D                             
2. A, C and D
3. A, B and C                             
4. A, B, C and D