The electronic configuration of the elements A and B are 1s², 2s ²,2p⁶,3s² and 1s², 2s²,2p⁵ respectively. The formula of the ionic compound that can be formed between these elements is ___________

(a)

AB

(b)

AB₂

(c)

A₂B

(d)

none of the above

The group of elements in which the differentiating electron enters the anti penultimate shell of atoms are called ___________

(a)

p-block elements

(b)

d-block elements

(c)

s-block elements

(d)

f-block elements

In which of the following options the order of arrangement does not agree with the variation of property indicated against it?

(a)

I< Br < CI < F (increasing electron gain enthalpy)

(b)

Li < Na < K < Rb (increasing metallic radius)

(c)

Al³⁺< Mg²⁺ < Na⁺ - (increasing ionic size)

(d)

B < C < O < N (increasing first ionisation enthalpy)

Which of the following elements will have the highest electro negativity ____________

(a)

Chlorine

(b)

Nitrogen

(c)

Cesium

(d)

Fluorine

Various successive ionisation enthalpies (in kJ mol^-1) of an element are given below.

IE1	IE2	IE3	IE4	IE5
577.5	1,810	2,750	11,580	14,820

The element is

(a)

phosphorus

(b)

Sodium

(c)

Aluminium

(d)

Silicon

In the third period the first ionization potential is of the order

(a)

Na > Al > Mg > Si > P

(b)

Na< AI < Mg < Si < P

(c)

Mg > Na > Si > P > Al

(d)

Na < AI < Mg < Si < P

The correct order of electron gain enthalpy with negative sign of F, CI, Br and I having atomic number 9,17,35 and 53 respectively

(a)

I > Br > CI > F

(b)

F > CI > Br > I

(c)

CI > F > Br > I

(d)

Br > I> CI > F

Which one of the following is the least electronegative element?

(a)

Bromine

(b)

Chlorine

(c)

Iodine

(d)

Hydrogen

The element with positive electron gain enthalpy is

(a)

Hydrogen

(b)

Sodium

(c)

Argon

(d)

Fluorine

The correct order of decreasing electronegativity values among the elements X, Y, Z and A with atomic numbers 4, 8,7 and 12 respectively

(a)

Y > Z > X > A

(b)

Z > A >Y > X

(c)

X > Y > Z > A

(d)

X > Y > A > Z

The electronic configuration of the atom having maximum difference in first and second ionisation energies is

(a)

1s₂, 2s₂, 2p⁶ 3s¹

(b)

1s², 2s²,2p⁶, 3s²

(c)

1s², 2s²,2p⁶, 3s², 3s², 3p⁶, 4s¹

(d)

Is², 2s²,2p⁶, 3s², 3p¹

Which of the following is second most electronegative element?

(a)

Chlorine

(b)

Fluorine

(c)

Oxygen

(d)

Sulphur

In a given shell the order of screening effect is

(a)

s > p > d > f

(b)

s > p > f > d

(c)

f > d > p > s

(d)

f > p > s > d

Which of the following orders of ionic radii is correct

(a)

H^- > H⁺ > H

(b)

Na⁺ > F^- > O^2-

(c)

F > O^2- > Na⁺

(d)

None of these

Assertion: Helium has the highest value of ionisation energy among all the elements known
Reason: Helium has the highest value of electron affinity among all the elements known

(a)

Both assertion and reason are true and reason is correct explanation for the assertion

(b)

Both assertion and reason are true but the reason is not the correct explanation for the assertion

(c)

Assertion is true and the reason is false

(d)

Both assertion and the reason are false

Define modern periodic law.

What are isoelectronic ions? Give examples.

What is effective nuclear charge?

Magnesium loses electrons successively to form Mg⁺, Mg²⁺ and Mg³⁺ ions. Which step will have the highest ionisation energy and why?

Define electro negativity.

Give the general electronic configuration of lanthanides and actinides.

What is the basic difference in approach between Mendeleev's periodic table and modern periodic table?

The element with atomic number 120 has not been discovered so far. What would be the IUPAC name and the symbol for this element? Predict the possible electronic configuration of this element.

The electron gain enthalpy of chlorine is 348 kJ mol^-1. How much energy in kJ is released when 17.5 g of chlorine is completely converted into Cl^- ions in the gaseous state?

Energy of an electron in the ground state of the hydrogen atom is -2.8 x 10^-18 J. Calculate the ionisation enthalpy of atomic hydrogen in terms of kJ mol^-1.

The electronic configuration of atom is one of the important factor which affects the value of ionisation potential and electron gain enthalpy. Explain.

In what period and group will an element with Z = 118 will be present?

Justify that the fifth period of the periodic table should have 18 elements on the basis of quantum numbers.

Elements a, b, c and d have the following electronic configurations:
a: 1s², 2s², 2p⁶
b: 1s², 2s², 2p⁶, 3s², 3p¹
c: 1s², 2s², 2p⁶, 3s², 3p⁶
d: 1s², 2s², 2p¹
Which elements among these will belong to the same group of periodic table.

Why halogens act as oxidising agents?

Mention any two anomalous properties of second period elements.

Predict the periods and blocks to which each of the following elements belongs?
(i) ₁₃Al
(ii) ₂₄Cr
(iii) ₂₉Cu
(iv) ₁₁Na

A student reported the ionic radii of isoelectronic species X³⁺,Y²⁺ and Z^- as 136 pm,64 pm and 49 pm respectively.Is that oreder correct?Comment

1. Explain the pauling method for the determination of ionic radius.

2. Explain the periodic trend of ionisation potential.

1. Explain the diagonal relationship.

2. Why the first ionisation enthalpy of sodium is lower than that of magnesium while its second ionisation enthalpy is higher than that of magnesium.

1. By using paulings method calculate the ionic radii of K⁺ and CI^- ions in the potassium chloride crystal. Given that dk⁺-cl^-=3.14 Å. 

2. Explain the following, give appropriate reasons.
   (i) Ionisation potential of N is greater than that of O.
   (ii) First ionisation potential of C-atom is greater than that of B atom, where as the reverse is true is for second ionisation potential.
   (iii) The electron affinity values of Be, Mg and noble gases are zero and those of N (0.02 eV) and P (0.80 eV) are very low.
   (iv) The formation of F-(g) from F(g) is exothermic while that of O^2-(g) from O (g) is endothermic.

1. What is screening effect? Briefly give the basis for pauling's scale of electronegativity.

2. State the trends in the variation of electronegativity in group and periods.

1. I.E increases as we move across the period but Ionisation enthalpies (I.E) of second period of elements in the order.
   Li < B < Be < C < O < N < F < Ne
   Explain why?
   (i) Be has higher I.E and B
   (ii) O has lower I.E than N & F

2. Using Slater's rule calculate the effective nuclear charge on a 3p electron in aluminium and chlorine. Explain how these results relate to the atomic radius of the two atoms.