Bloggold238

• Formula: F₂
• Molecular weight: 37.9968064
• IUPAC Standard InChI:
  

  InChI=1S/F2/c1-2 Download the identifier in a file.

• IUPAC Standard InChIKey:PXGOKWXKJXAPGV-UHFFFAOYSA-N
• CAS Registry Number: 7782-41-4
• Chemical structure:
  This structure is also available as a 2d Mol fileor as a computed3d SD file
  The 3d structure may be viewed usingJavaorJavascript.
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Gas phase ion energetics data

Go To:Top, References, Notes

Data compilation copyrightby the U.S. Secretary of Commerce on behalf of the U.S.A.All rights reserved.

Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias

Ionization energy, also called ionization potential, is the energy necessary to remove an electron from the neutral atom. X + energy → X + + e −. Where X is any atom or molecule capable of being ionized, X + is that atom or molecule with an electron removed (positive ion), and e − is the removed electron. A Fluorine atom, for example. Fluorine has higher ionization energy than iodine because the size of fluorine is smaller than the iodine. This means that the shielding effect is less for fluorine. Therefore, the nucleus attracts more valence electrons in fluorine than in iodine. Stay tuned with BYJU’S to learn more about other concepts such as ionization energy. The approximate ionization energy, in Rydberg atomic units, is then simply given by Z r i.e. 1 for hydrogen and Z − 8 r, or 1.281 for fluorine, with each electron shielding exactly one proton. (Multiply by 1313 to convert to kJ/mol). Electron affinity of Fluorine is 328 kJ/mol.

The Fluorine Ionization Energy is the energy required to remove from atom one mole of electrons with subsequent production of positively charged ion of Fluorine. F - F + + e- This process can be repeated many times, but the energy cost is increased dramatically. The general equation for the Fluorine is.

Data compiled as indicated in comments:
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
LL - Sharon G. Lias and Joel F. Liebman
B - John E. Bartmess

Electron affinity determinations

Ionization energy determinations

Appearance energy determinations

References

Go To:Top, Gas phase ion energetics data, Notes

Data compilation copyrightby the U.S. Secretary of Commerce on behalf of the U.S.A.All rights reserved.

Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G.,Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update,J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018. [all data]

Wenthold and Squires, 1995
Wenthold, P.G.; Squires, R.R.,Bond dissociation energies of F2(-) and HF2(-). A gas-phase experimental and G2 theoretical study,J. Phys. Chem., 1995, 99, 7, 2002, https://doi.org/10.1021/j100007a034. [all data]

Artau, Nizzi, et al., 2000
Artau, A.; Nizzi, K.E.; Hill, B.T.; Sunderlin, L.S.; Wenthold, P.G.,Bond dissociation energy in trifluoride ion,J. Am. Chem. Soc., 2000, 122, 43, 10667-10670, https://doi.org/10.1021/ja001613e. [all data]

Ayala, Wentworth, et al., 1981
Ayala, J.A.; Wentworth, W.E.; Chen, E.C.M.,Electron attachment to halogens,J. Phys. Chem., 1981, 85, 768. [all data]

Harland and Franklin, 1974
Harland, P.W.; Franklin, J.L.,Partitioning of excess energy in dissociative resonance capture processes,J. Chem. Phys., 1974, 61, 1621. [all data]

DeCorpo and Franklin, 1971
DeCorpo, J.J.; Franklin, J.L.,Electron affinities of the halogen molecules by dissociative electron attachment,J. Chem. Phys., 1971, 54, 1885. [all data]

Wang and Franklin, 1980
Wang, J.-S.; Franklin, J.L.,Reactions and energy distributions in dissociative electron capture processes in sulfuryl halides,Int. J. Mass Spectrom. Ion Phys., 1980, 36, 233. [all data]

Thynne, 1972
Thynne, J.C.J.,Negative Ion Studies with a Time-of-Flight Mass Spectrometer.,Dyn. Mass Spectrom., 1972, 3, 67. [all data]

Chupka, Berkowitz, et al., 1971
Chupka, W.A.; Berkowitz, J.; Gutman, D.,Electron Affinities of Halogen Diatomic Molecules as Determined by Endoergic Charge Exchange,J. Chem. Phys., 1971, 55, 6, 2724, https://doi.org/10.1063/1.1676487. [all data]

Reese, Dibeter, et al., 1958
Reese, R.M.; Dibeter, V.H.; Franklin, J.L.,Electron impact studies of sulfur dioxide and sulfuryl fluoride,J. Chem. Phys., 1958, 29, 880. [all data]

Van Lonkhuyzen and De Lange, 1984
Van Lonkhuyzen, H.; De Lange, C.A.,High-resolution UV photoelectron spectroscopy of diatomic halogens,Chem. Phys., 1984, 89, 313. [all data]

Bieri, Schmelzer, et al., 1980
Bieri, G.; Schmelzer, A.; Asbrink, L.; Jonsson, M.,Fluorine and the fluoroderivatives of acetylene and diacetylene studied by 30.4 nm He(II) photoelectron spectroscopy,Chem. Phys., 1980, 49, 213. [all data]

Guyon, Spohr, et al., 1976
Guyon, P.-M.; Spohr, R.; Chupka, W.A.; Berkowitz, J.,Threshold photoelectron spectra of HF, DF, F₂,J. Chem. Phys., 1976, 65, 1650. [all data]

Gole and Margrave, 1972
Gole, J.L.; Margrave, J.L.,The vacuum ultraviolet spectrum of molecular fluorine,J. Mol. Spectrosc., 1972, 43, 65. [all data]

Potts and Price, 1971
Potts, A.W.; Price, W.C.,Photoelectron spectra of the halogens and mixed halides ICI and lBr,J. Chem. Soc. Faraday Trans., 1971, 67, 1242. [all data]

Cornford, Frost, et al., 1971
Cornford, A.B.; Frost, D.C.; McDowell, C.A.; Ragle, J.L.; Stenhouse, I.A.,Photoelectron spectra of the halogens,J. Chem. Phys., 1971, 54, 2651. [all data]

Berkowitz, Chupka, et al., 1971
Berkowitz, J.; Chupka, W.A.; Guyon, P.M.; Holloway, J.H.; Spohr, R.,Photoionization mass spectrometric study of F₂, HF, and DF,J. Chem. Phys., 1971, 54, 5165. [all data]

Anderson, Mamantov, et al., 1971
Anderson, C.P.; Mamantov, G.; Bull, W.E.; Grimm, F.A.; Carver, J.C.; Carlson, T.A.,Photoelectron spectrum of chlorine monofluoride,Chem. Phys. Lett., 1971, 12, 137. [all data]

Dibeler, Walker, et al., 1969
Dibeler, V.H.; Walker, J.A.; McCulloh, K.E.,Dissociation energy of fluorine,J. Chem. Phys., 1969, 50, 4592. [all data]

Iczkowski and Margrave, 1959
Iczkowski, R.P.; Margrave, J.L.,Absorption spectrum of fluorine in the vacuum ultraviolet,J. Chem. Phys., 1959, 30, 403. [all data]

Dyke, Josland, et al., 1984
Dyke, J.M.; Josland, G.D.; Snijders, J.G.; Boerrigter, P.M.,Ionization energies of the diatomic halogens and interhalogens studied with relativistic hartree-fock-slater calculations,Chem. Phys., 1984, 91, 419. [all data]

Veljkovic, Neskovic, et al., 1992
Veljkovic, M.V.; Neskovic, O.M.; Zmbov, K.F.,Mass spectrometric study of the thermal decomposition of F₂,J. Serb. Chem. Soc., 1992, 57, 753. [all data]

Berkowitz and Wahl, 1973
Berkowitz, J.; Wahl, A.C.,The dissociation energy of fluorine,Adv. Fluorine Chem., 1973, 7, 147. [all data]

Berkowitz, Chupka, et al., 1971, 2
Berkowitz, J.; Chupka, W.A.; Guyon, P.M.; Holloway, J.; Spohr, R.,Photo-ionization studies of F₂, HF, DF, and the xenon fluorides,Advan. Mass Spectrom., 1971, 5, 112. [all data]

Notes

Go To:Top, Gas phase ion energetics data, References

• Symbols used in this document:
  

  AE	Appearance energy
  EA	Electron affinity
  IE (evaluated)	Recommended ionization energy

• Data from NIST Standard Reference Database 69:NIST Chemistry WebBook
• The National Institute of Standards and Technology (NIST)uses its best efforts to deliver a high quality copy of theDatabase and to verify that the data contained therein havebeen selected on the basis of sound scientific judgment.However, NIST makes no warranties to that effect, and NISTshall not be liable for any damage that may result fromerrors or omissions in the Database.
• Customer supportfor NIST Standard Reference Data products.

1) Which of the following order is correct for the first ionization energies of following elements? (EAMCET 2009)

1) B < Be < N < O

2) Be < B < N < O

3) B < Be < O < N

4) B < O < Be < N

Logic:

* Ionization energy, in general, increases with decrease in the atomic radius across the period from left to right. However there are exceptions.

* s-orbitals have greater penetration power than p-orbitals. Hence the removal of electrons from s-orbitals require more energy.

* The electrons in half filled orbitals are stable as they experience less repulsion. If there is another electron sharing same orbital, then they will be destabilized due to repulsion from each other.

* Above atoms belong to same period (2nd) of periodic table.

Solution:

* Boron, B is smaller than beryllium, Be atom. Hence we expect increase in ionization energy from Be to B.

However, Be atom has greater ionization energy than B atom. The reason is - in case of Beryllium, the last electron is in the s-orbital and in Boron, the last electron is in the p-orbital. We know that removal of electron from s-orbital requires more energy than the electron from p-orbital.

* 2s²2p³ configuration is more stable than 2s²2p⁴ due to half filled p-sublevel. The electrons in the p-orbital in N atom experience less repulsion, thus more stable and more ionization energy. Whereas in case of O atom the 4th p-electron atom can be removed more easily as it experiences more repulsion from the electrons in the p-orbitals already present. Hence nitrogen, Oxygen atom has less ionization energy than Nitrogen atom.

Conclusion:

The correct ionization energy order is: B < Be < O < N

(new) Click here to see 3d Interactive Solved Question paper

Followup Practice questions on Ionization potential

2) The first ionization potential of four consecutive elements, present in the second period of the periodic table are 8.3, 11.3, 14.5 and 13.6 eV respectively. Which one of the following is the first ionization potential (in eV) of nitrogen?

(Eamcet - 2004-M)

1) 13.6

2) 11.3

3) 8.3

4) 14.5

Logic & solution:

The ionization energies increase regularly for the first three elements. Then there is decrease in the IE value from 3rd to 4th element. This indicates, 3rd element must possess stable configuration. Hence the third element is nitrogen.

Conclusion:

The first ionization potential (in eV) of nitrogen is 14.5. The correct option is '4'.

3) The electron configuration of elements A, B and C are [He]2s¹, [Ne]3s¹ and [Ar]4s¹ respectively. Which one of the following order is correct for the first ionization potentials (in kJ mol^–1) of A, B and C?

(Eamcet - 2001-E)

1) A > B > C

2) C > B > A

3) B > C >A

4) C > A > C

Logic & solution:

The electronic configurations clearly indicate that they belong to same group of periodic table i.e. 1st group. The atomic size increases with increase in the value of principal quantum number, n of valence orbital (from 2 to 3 to 4). Hence the ionization energy decreases from A to B to C.

Conclusion:

The correct option is '1'.

4) The correct order of second ionization energies of C, N, O and F is:

(IIT JEE 1991)

1) C > N > O > F

2) O > N > F > C

3) O > F > N > C

4) F > O > N > C

Logic & solution:

The second ionization energy refers to the energy required to remove the electron from the corresponding mono-valent cation of the respective atom. The atoms: C, N, O and F belong to 2nd period of the periodic table.

Just like second ionization energy like the first IE is affected by size, effective nuclear charge, type of orbital from which the electron is being removed and electronic configuration.

It is expected to increase from left to right in the periodic table with decrease in the atomic size. However oxygen has greater second ionization energy than fluorine and also nitrogen.

Reason: Since Oxygen atom gets stable electronic configuration, 2s²2p³ after removing one electron, the O⁺ shows greater ionization energy than F⁺ as well as N⁺.

Hence the order of second ionization energies of above elements is: O > F > N > C.

Conclusion:

The correct option is '3'.

5)The incorrect statement among the following is:

(IIT JEE 1997)

1) The first ionization potential of Al is less than the first ionization potential of Mg.

2) The second ionization potential of Mg is greater than the second ionization potential Na.

3) The first ionization potential of Na is less than the first ionization potential of Mg.

4) The third ionization potential of Mg is greater than that of Al.

Logic & solution:

The outer electronic configurations of atoms, univalent and divalent cations of elements mentioned in above statement are tabulated below.

Statement-1 is correct since, the electron has to be removed from full filled s-orbital, the first ionization energy of Mg is greater than that of Al.

Statement-2 is incorrect since Na⁺ has now stable octet configuration(2s²2p⁶) and requires greater energy to remove second electron than in case of Mg⁺.

Statement-3 is correct because Mg is smaller than Na and has greater effective nuclear charge. Hence the first ionization energy of Mg is higher.

Statement-4 is also correct. It is because of stable octet configuration of Mg²⁺ formed after removing two electrons from Mg.

Conclusion:

The correct option is 2 ( the statement given is incorrect).

6) The first ionization potentials of Na, Mg, Al and Si are in the order:

(IIT JEE 1988)

1) Na < Mg > Al < Si

2) Na < Mg < Al > Si

3) Na > Mg > Al > Si

4) Na > Mg > Al < Si

Logic & solution:

They belong to same period. We can expect increase in ionization energy from Na to Si. Yet, Mg has greater ionization energy than Al due to 2s²2p⁶3s² configuration. It is more difficult to remove electron from 3s orbital than from 3p orbital since s-orbitals have greater penetration power. Moreover, Mg has stable electronic configuration with full filled 3s orbital.

Conclusion:

The correct first ionization energy order is shown in the option '1'.

7) The first ionization energy in electron volts of nitrogen and oxygen atom's are respectively given by:

(IIT JEE 1987)

a) 14.6, 13.6

b) 13.6, 14.6

c) 13.6, 13.6

d) 14.6, 14.6

Logic & solution:

Since nitrogen has greater ionization energy than oxygen, the correct option is 'a'.

8) Which of the following species has the highest ionization potential?

(EAMCET 1998-E)

1) Li⁺

2) Mg⁺

3) Al⁺

4) Ne

Logic & solution:

Li⁺ has 1s² configuration, which is the configuration of He atom. Hence it should possess highest IP value.

Conclusion:

The correct option is '1'.

9) The set representing correct order of first ionization potential is:

(IIT JEE 2001)

1) K > Na > Li

2) Be > Mg > Ca

3) B > C > N

4) Ge > Si > C

Logic & solution:

1) K > Na > Li : Incorrect, since ionization energy decreases down the group with increase in size. These elements belong to same group (1st). The correct order of first ionization energy should be: K < Na < Li.

2) Be > Mg > Ca : Correct. These are 2nd group elements and the order correctly reflects trend in ionization energy.

3) B > C > N: Incorrect. They belong to same period and the order should be reverse since the IP values increase from left to right in a period.

4) Ge > Si > C : Incorrect: Belong to same group (14th).The order must be in reverse.

Conclusion:

The correct option is '2'.

10) Amongst the following elements (whose electronic configurations are given below), the one having the highest ionization energy is:

(IIT JEE 1990)

a) [Ne] 3s² 3p¹

b) [Ar] 3d¹⁰ 4s² 4p²

c) [Ne] 3s² 3p²

d) [Ne] 3s² 3p³

Logic & solution:

Based on electronic configuration of elements, their positions in the periodic table can be assigned as shown below.

The element with electronic configuration [Ne] 3s² 3p³ is on the extreme right and with stable 3p³ configuration (half filled sub level). Hence it should have highest IE value.

Conclusion:

The correct option is 'd'.

11) The increasing order of the first ionization enthalpies of the elements B, P, S and F (lowest first) is:

(AIEEE 2006)

a) F < S < P < B

b) P < S < B < F

c) B < P < S < F

d) B < S < P < F

Logic & solution:

Fluorine, being the smallest has the highest ionization enthalpy among the given elements.

Phosphorus has 3s²3p³ configuration with half filled p-sub level. Hence it has higher IP value than Sulfur.

Conclusion:

The correct option is 'd'.

12) The correct order of ionization energy for the following species is:

(AdiChemistry IIT JEE NEET 2018)

1) He < Li⁺ < H^-

2) H^- < Li⁺ < He

3) H < Li⁺ < He

4) H^- < He < Li⁺

Logic & solution:

All the species have the same electronic configuration i.e. 1s². But theenergy required to remove the outer electron increases with decrease in the negative charge (or increase in the positive charge).

Conclusion:

The correct option is 4.

13) Which of the following atoms has the highest first ionization energy?

(IIT JEE MAIN 2016)

(1) Na

(2) K

(3) Sc

(4) Rb

Logic & solution:

All the atoms, except scandium belong to alkali metals. Scandium belongs to 3rd group (II B). it is a of d-block element - a transition metal. Its atomic radius is smaller than the other given atoms. Hence it is expected to have higher ionization energy among the given options.

Conclusion:

The correct option is 3.

IONIZATION ENERGY - FOLLOWUP PRACTICE QUESTIONS & PROBLEMS WITH ANSWERS

1) The increasing order of second ionization energies of Na, Ne, Mg and Al is __________ .

Answer: Na > Ne > Al > Mg

Information: The second ionization energies (in kJ mol^-1) are: Na (4563), Ne (3963), Al (1820), Mg (1450).

2) The correct increasing order of effective nuclear charge among the elements O, F, Ne, C, N is _______ .

Answer: C < N < O < F < Ne

Second Ionization Energy Of Fluorine

Explanation: On moving from left to right in the periodic table in a period, the effective nuclear charge increases.

3) Lowest IP will be shown by the element having the configuration:

A) [He] 2s²

Ionization Energy Of Fluorine Ion

B) [He] 2s² 2p²

C) 1s²

D) [He] 2s² 2p³

Answer: B

4) Which element in the periodic table has the highest ionization potential?

Answer: Helium (He) has the highest first ionization energy (IE₁).

5) The electronic configuration with the highest ionization enthalpy is ________

First Ionization Energy Of Fluorine Equation

Answer: 1s².

6) Which of the following has maximum ionisation potential ?

A) F

B) Mg²⁺

C) He⁺

D) Li⁺

Answer: D

Information: Ionization potential values in kJ/mol: F (1680), Mg²⁺ (1450), He⁺ (5250), Li⁺ (7292)

7) Which of the following is the correct sequence for increasing order (i.e. smallest to largest) of first ionization energy (IE₁)?

A) O > C > F

B) O > N > F

C) N > C > F

D) F > N > O

Answer: D

2) What is the relation between ionization potential and effective nuclear charge experienced by an electron in nth orbit?

3) What is the general trend observed in ionization energy in alkali and alkaline earth metals?