The formula for the oxide formed by Eka-aluminum is:

1. ${\mathrm{EO}}_4$

2. ${\mathrm{E}}_2{\mathrm{O}}_3$

3. ${\mathrm{E}}_3{\mathrm{O}}_2$

4. EO

In which of the following molecule, the internuclear distance will be maximum:
1. CsI
2. CsF
3. LiF
4. LiI

The first ionization potential of Be and B will be:

1.  8.8 and 8.8
2.  6.6 and 6.6
3.  6.6 and 8.8
4.  8.8. and 6.6

An electronic configuration that has maximum difference between II and III ionization potential is:

1. 1s² 2s² 2p⁶ 3s¹

2. 1s² 2s² 2p⁶ 3s²

3. 1s² 2s² 2p⁶

4. 1s² 2s² 2p⁵

Incorrect order among the following is:

1. NH₃ < PH₃ < AsH₃ – Acidic

2. Li < Be < B < C – I^st Ionization potential

3. Al₂O₃ < MgO < Na₂O < K₂O - Basic

4. Li⁺ < Na⁺ < K⁺ < Cs⁺ - Ionic radius

If an atom has electronic configuration 1s²2s²2p⁶3s²3p⁶3d³4s², we will place it in group number:

The correct order of $I^{st}$ IP(ionization potential) among the following elements Be, B, C, N, O is:

The basic theme of the periodic table is:

Property used by Mendeleev to classify the elements was -

1. Brightness

2. Atomic weight or mass

3. Number of isotopes

4. Lustre

The basic difference between Mendeleev’s Periodic Law (A) and Modern Periodic Law (B) is: