Among isoelectronic monoatomic species, size is inversely proportional to atomic number. Hence among isoelectronic species Na? , O²? , N³? , F? (having the nearest noble gas configuration);
Order of size is Na? < F? < O²? < N³?
N³? has least atomic number hence the largest size

The order of electron gain enthalpy in kJ/mol of fluorine, chlorine, bromine and iodine, respectively are

Vishal Baghel

Electron gain enthalpy increases with electro negativity chlorine has higher electron gain enthalpy than fluorine (exception)

The correct order of the ionic radii of O²⁻, N³⁻, F⁻, Mg²⁺, Na⁺ and Al³⁺ is:

Vishal Baghel

In isoelectronic species nuclear charge can be approximated as
Nuclear charge ≈ z / no. of electrons
Al³? Mg²? Na? F? O²? N³?
Nuclear Charge: 13/10 12/10 11/10 9/10 8/10 7/10
Minimum nuclear charge is in N³? and maximum is in Al³?
So order should be
Al³? < Mg²? < Na? < F? < O²? < N³?

3.31. The first (ΔiH₁) and the second (ΔiH₂) ionization enthalpies (in kJ mol^–1) and the (Δ_egH) electron gain enthalpy (in kJ mol^–1) of a few elements are given below:

Elements ΔH1 ΔH2 Δ_egH

I 520 7300 –60

II 419 3051 –48

III 1681 3374 –328

IV 1008 1846 –295

V 2372 5251 +48

VI 738 1451 –40

Which of the above elements is likely to be:

(a) The least reactive element

(b) The most reactive metal

(c) The most reactive non-metal

(d) The least reactive non-metal

(e) The metal which can form a stable binary halide of the formula MX₂(X = halogen)

(f) The metal which can form a predominantly stable covalent halide of the formula MX (X = halogen)?

Payal Gupta

(a) The element V has the highest first ionization enthalpy (? _iH₁) and positive electron gain enthalpy (? _egH) and hence it is the least reactive element. Since inert gases have positive? _egH, therefore, the element-V must be an inert gas. The values of? _iH₁, ? _iH₂ and? _egH match that of He.

(b) The element II which has the least first ionization enthalpy (? _iH₁) and a low negative electron gain enthalpy (? _egH) is the most reactive metal. The values of ? _iH₁, ? _iH₂ and? _egH match that of K (potassium).

(c) The element III which has high fi

...more

Electronic configuration of some elements is given in Column I and their electron gain enthalpies are given in Column II. Match the electronic configuration with electron gain enthalpy.

Column (I)	Column (II)
Electronic configuration	Electron gain enthalpy/kJ mol^–1
(i) 1s²2s²sp⁶	(A) – 53
(ii) 1s² 2s² 2p⁶ 3s¹	(B) – 328
(iii) 1s²2s² 2p⁵	(C) – 141
(iv) 1s² 2s² 2p⁴	(D) + 48

alok kumar singh

This is a Matching Type Questions as classified in NCERT Exemplar

i d + 48

ii a &n

...more

Get authentic answers from experts, students and alumni that you won't find anywhere else

On Shiksha, get access to

65k Colleges
1.2k Exams
687k Reviews
1800k Answers

Community GuidelinesUser Points System

QuestionsDiscussionsTags

3.27. Use periodic table to answer the following questions:

(a) Identify the element with five electrons in the outer sub shell.

(b) Identify the element that would tend to lose two electrons.

(c) Identify the element that would tend to gain two electrons.

1 Answer

Similar Questions for you

Learn more about...

Most viewed information

Share Your College Life Experience

Didn't find the answer you were looking for?

Need guidance on career and education? Ask our experts

Your Question

3.27. Use periodic table to answer the following questions: (a) Identify the element with five electrons in the outer sub shell. (b) Identify the element that would tend to lose two electrons. (c) Identify the element that would tend to gain two electrons.