Why the ionization enthalpy decreases down the group ?

Why the ionization enthalpy decreases down the group ? 
by

1 Answer

Answer :

This is because, the Increase in atomic size is more predominant over increasing nuclear charge and the outer most electrons are very well screened from the nuclear charge by the inner shell electrons 
by

Related questions

Define ionization enthalpy. Name the factors on which ionisation enthalpy depends? How does it vary down the group and across a period?

Description : Define ionization enthalpy. Name the factors on which ionisation enthalpy depends? How does it vary down the group and across a period?

Last Answer : Define ionization enthalpy. Name the factors on which ionisation enthalpy depends? How does it vary down the group and across a period?

From the elements: Cl, Br, F, O, Al, C, Li, Cs and Xe; choose the following: (a) The element with highest negative electron gain enthalpy. (b) The element with lowest ionization enthalpy. (c) The element with smallest ionic radius. (d) The element with six electrons in the valence shell. (e) The element which is a liquid at room temperature. (f)The element which belongs to zero group. (g) The elements which forms largest number of compounds.

Description : From the elements: Cl, Br, F, O, Al, C, Li, Cs and Xe; choose the following: (a) The element with highest negative electron gain enthalpy. (b) The element with lowest ionization enthalpy. ( ... . (f)The element which belongs to zero group. (g) The elements which forms largest number of compounds.

Last Answer : Ans. (a). The element chlorine (Cl) has the highest negative electron gain enthalpy. (b). The element cesium (Cs) has lowest ionization enthalpy. (c). The element fluorine F has lowest atomic radius. (d ... zero group (or group 18). (g). The element carbon (C) forms the largest number of compounds.

Which group elements show very low ionization enthalpy in the periodic table?

Description : Which group elements show very low ionization enthalpy in the periodic table?

Last Answer : First group elements (alkali metals) 

The order of Ionization enthalpy between following atoms is?

Description : The order of Ionization enthalpy between following atoms is?

Last Answer : B, Tl, Ga, Al and In. Ans.B>Tl>Ga> Al> In.

How does the of Ionization Enthalpy of alkaline earth metals vary in comparison to alkali metals

Description : How does the of Ionization Enthalpy of alkaline earth metals vary in comparison to alkali metals

Last Answer : Ans The alkaline earth metals have low ionization enthalpies due to fairly large size of the atoms. Since the atomic size increases down the group, their ionization enthalpy decreases The first ... enthalpies of the alkaline earth metals are smaller than those of the corresponding alkali metals.

From each set, choose the element with largest ionization enthalpy and explain your answer. (a) F, O, N (b) Mg, P, Ar (c) B, Al, Ga

Description : From each set, choose the element with largest ionization enthalpy and explain your answer. (a) F, O, N (b) Mg, P, Ar (c) B, Al, Ga

Last Answer : Ans. (a). The element fluorine F has the largest ionization enthalpy because in general, it increases along the period. These elements belong to the second period in the order is: N, O, F. Therefore, ... the order of B, Al, Ga. Therefore, the first element B is expected to have the largest value.

Arrange the following order of the property indicated: (a). F, Cl, Br and I (negative electron gain enthalpy) (b). Mg, Al, Si and Na (ionization enthalpy) (c). C, N, O and F (second ionization enthalpy)

Description : Arrange the following order of the property indicated: (a). F, Cl, Br and I (negative electron gain enthalpy) (b). Mg, Al, Si and Na (ionization enthalpy) (c). C, N, O and F (second ionization enthalpy)

Last Answer : Ans. (a). I

(a). Which is largest in size- Cu+ , Cu+2, Cu and why? (b). which element in the periodic table has the highest ionization enthalpy? (c). Which element is more metallic in the periodic table.?

Description : (a). Which is largest in size- Cu+ , Cu+2, Cu and why? (b). which element in the periodic table has the highest ionization enthalpy? (c). Which element is more metallic in the periodic table.?

Last Answer : Ans. (a). Cu is largest due to less effective nuclear charge. It has 29 electrons, 29 protons, Cu+ has 28 electrons and 29 protons, Cu2+ has 27 electrons and 29 protons. (b). He has highest ionization enthalpy. (c). Mg is more metallic due to lower ionization energy

Among the elements of the 3rd period from Na to Ar, pick out the element: (L-2) (a). with highest first ionization enthalpy. (b). with largest atomic radius. (c). that is most reactive non-metal. (d). that is most reactive metal.

Description : Among the elements of the 3rd period from Na to Ar, pick out the element: (L-2) (a). with highest first ionization enthalpy. (b). with largest atomic radius. (c). that is most reactive non-metal. (d). that is most reactive metal.

Last Answer : (a). Ar has highest first ionization enthalpy. (b). Na has large atomic radius (covalent radius). (c). Cl is more reactive non-metal in 3rd period. (d). Na is most reactive metal in third period.

How does the of Ionization Enthalpy of alkaline earth metals vary in comparison to alkali metals

Description : How does the of Ionization Enthalpy of alkaline earth metals vary in comparison to alkali metals 

Last Answer : The alkaline earth metals have low ionization enthalpies due to fairly large size of the atoms. Since the atomic size increases down the group, their ionization enthalpy decreases The first ionisation ... of the alkaline earth metals are smaller than those of the corresponding alkali metals.  

How the ionization enthalpy varies in alkali metals

Description : How the ionization enthalpy varies in alkali metals 

Last Answer : Ionization enthalpy decrease down the group from Li to Cs. 

In general, as you move down a family the ionization energy: w) increases x) decreases y) remains the same z) increases or decreases

Description : In general, as you move down a family the ionization energy: w) increases x) decreases y) remains the same z) increases or decreases

Last Answer : ANSWER: X -- DECREASES

Which element from the following pairs has higher ionization enthalpy? B and TI, N and Bi

Description : Which element from the following pairs has higher ionization enthalpy? B and TI, N and Bi

Last Answer : Which element from the following pairs has higher ionization enthalpy? B and TI, N and Bi

a. Which atom should have smaller ionization enthalpy, oxygen or sulfur? b. The lithium forms +1 ions while berylium forms +2 ions ?

Description : a. Which atom should have smaller ionization enthalpy, oxygen or sulfur? b. The lithium forms +1 ions while berylium forms +2 ions ?

Last Answer : With the help of diagram answer the questions given below : a. Which atom should have smaller ... forms +1 ions while berylium forms +2 ions ?

Ionization enthalpy of Li is 520 kJ mol^(-1) while that of F is 1681 kJ mol^(-1) . Explain.

Description : Ionization enthalpy of Li is 520 kJ mol^(-1) while that of F is 1681 kJ mol^(-1) . Explain.

Last Answer : Ionization enthalpy of Li is 520 kJ mol-1 while that of F is 1681 kJ mol-1. Explain.

Why the second ionization enthalpy is greater than the first ionization enthalpy ?

Description : Why the second ionization enthalpy is greater than the first ionization enthalpy ?

Last Answer : Why the second ionization enthalpy is greater than the first ionization enthalpy ?

AS A GROUP, the halogens have the largest: w) atomic radii x) Boiling points y) electronegativities z) ionization energies

Description : AS A GROUP, the halogens have the largest: w) atomic radii x) Boiling points y) electronegativities z) ionization energies

Last Answer : ANSWER: Y -- ELECTRONEGATIVITIES

Assertion :- Entropy of system increases for a spontaneous reactions. Reason :- Enthalpy of reaction always decreases for spontaneous reaction.

Description : Assertion :- Entropy of system increases for a spontaneous reactions. Reason :- Enthalpy of reaction always decreases for spontaneous reaction.

Last Answer : Assertion :- Entropy of system increases for a spontaneous reactions. Reason :- Enthalpy of reaction ... D. If both Assertion & Reason are false.

__________ decreases during adiabatic throttling of a perfect gas. (A) Entropy (B) Temperature (C) Enthalpy (D) Pressure

Description : __________ decreases during adiabatic throttling of a perfect gas. (A) Entropy (B) Temperature (C) Enthalpy (D) Pressure

Last Answer : (D) Pressure

For an ideal gas, the enthalpy (A) Increases with rise in pressure (B) Decreases with rise in pressure (C) Is independent of pressure (D) Is a path function

Description : For an ideal gas, the enthalpy (A) Increases with rise in pressure (B) Decreases with rise in pressure (C) Is independent of pressure (D) Is a path function

Last Answer : (C) Is independent of pressure

Arrange the first group elements in the decreasing order of Hydration Enthalpy

Description : Arrange the first group elements in the decreasing order of Hydration Enthalpy 

Last Answer : The hydration enthalpies of alkali metal ions decrease with increase in ionic sizes. Li+ > Na+ > K+ > Rb+ > Cs+

Give reason for the following observation (L-III) (a)- The tendency for catenation decreases down the group in group 14 (b)- The decreasing stability of+3 oxidation state with increasing atomic no. in group 13. (c)- Molten aluminum bromide is a poor conductor of electricity.

Description : Give reason for the following observation (L-III) (a)- The tendency for catenation decreases down the group in group 14 (b)- The decreasing stability of+3 oxidation state with increasing atomic no. in group 13. (c)- Molten aluminum bromide is a poor conductor of electricity.

Last Answer : Ans. -(a) it is due to decrease in bond dissociation energy which is due to increase in atomic size C-C > Si-Si >Ge-Ge>Sn-Sn>Pb-Pb. (b)- It is due to inert pair effect. (c)- Molten AlBr3 is poor conductor of electricity because it is covalent compound.

An element has successive ionization enthalpies as 940 (first),2080,3090,4140,7030,7870,16000 and 19500 kJ `mol^(-1)`. To which group of the periodic

Description : An element has successive ionization enthalpies as 940 (first),2080,3090,4140,7030,7870,16000 and 19500 kJ `mol^(-1)`. To which group of the periodic

Last Answer : An element has successive ionization enthalpies as 940 (first),2080,3090,4140,7030,7870,16000 and 19500 kJ `mol^(- ... belong? A. 14 B. 15 C. 16 D. 17

Explain the trend of the following in group 13 elements : A. atomic radii  B. ionization enthalpy  C. electron affinity

Description : Explain the trend of the following in group 13 elements : A. atomic radii  B. ionization enthalpy  C. electron affinity

Last Answer : Explain the trend of the following in group 13 elements : A. atomic radii B. ionization enthalpy C. electron affinity

What are the trends of First ionization energy of group 2?

Description : What are the trends of First ionization energy of group 2?

Last Answer : What is the answer ?

Give IUPAC name of the ionization isomer of [Ni(NH3)3NO3]Cl. -Chemistry

Description : Give IUPAC name of the ionization isomer of [Ni(NH3)3NO3]Cl. -Chemistry

Last Answer : IUPAC name : Triammine chlorido nickel (II) nitrate [Ni(NH3)3NO3]Cl

Give IUPAC name of ionization isomer of [Ni(NH3)3NO3]Cl. -Chemistry

Description : Give IUPAC name of ionization isomer of [Ni(NH3)3NO3]Cl. -Chemistry

Last Answer : IUPAC name : Triammine nitrato nickel (III) chloride

Give an example of ionization isomerism. -Chemistry

Description : Give an example of ionization isomerism. -Chemistry

Last Answer : Example : [Pt (NH3)5 (Br)3] SO4 and [Co (NH3)5 (SO4)] Br

What is ionization energy ?

Description : What is ionization energy ?

Last Answer : The amount of energy required to move the most loosely connected electrons from an isolated atom of an element to an infinite distance in a gaseous state is called the ionization energy of that element.

Why is the ionization energy of IA class elements lowest at any stage ?

Description : Why is the ionization energy of IA class elements lowest at any stage ?

Last Answer : Any phase of the Periodic Table starts with Group- IA on the left . At any stage, from left to right, the value of ionization potential gradually increases due to atomic size contraction. For this reason, the ionization energy of the elements of the leftmost IA group is the lowest.

What is ionization ?

Description : What is ionization ?

Last Answer : The amount of energy required to remove electrons from the outermost energy level of an element and convert it into positive ions is called ionization of that element. Ionization energy is an important periodic property of the element.

What is the ionization energy of an element ?

Description : What is the ionization energy of an element ?

Last Answer : The amount of energy required to move the most loosely connected electrons from an isolated atom of an element to an infinite distance in a gaseous state is called the ionization energy of that element.

The element with highest first ionization energy is - (1) hydrogen (2) helium (3) lithium (4) sodium

Description : The element with highest first ionization energy is - (1) hydrogen (2) helium (3) lithium (4) sodium

Last Answer : (2) helium Explanation: The first ionisation energy is the energy required to remove the most loosely held electron from one mole of gaseous atoms to produce 1 mole of gaseous ions each with a charge of ... ) of Hydrogen: around 1200: Helium: about 2500; Lithium: about 500; and Sodium: about 500.

Which among the following is not a characteristic of transition metals? (1) Tendency to gain electrons (2) Low electronegativity (3) Low ionization energy (4) Malleability

Description : Which among the following is not a characteristic of transition metals? (1) Tendency to gain electrons (2) Low electronegativity (3) Low ionization energy (4) Malleability

Last Answer : (1) Tendency to gain electrons Explanation: The transition metals have a tendency to lose electrons. Since the electrons in the highest energy level are actually on a lower principal enemy number than the ... ions, the 4s electrons are always lost first; so, they form only cations (positive ions).

What is the difference between dissociation and ionization?

Description : What is the difference between dissociation and ionization?

Last Answer : Ans: The term ionization is used for the compounds which are covalent and when dissolve in the solution undergo dissociation where as for the ionic compounds which are in ionic form in the compound when dissolve into the solution undergo dissociation.

How much is the percentage ionization of an electrolyte to classified is as 'weak electrolyte'?

Description : How much is the percentage ionization of an electrolyte to classified is as 'weak electrolyte'?

Last Answer : Ans:

Among Li, Na, K, Rb, Cs, the element with lowest ionization energy is________

Description : Among Li, Na, K, Rb, Cs, the element with lowest ionization energy is________

Last Answer : Ans. Cs has lowest ionization enthalpy.

Define the following : Atomic Radii , Ionization Energy , Electron Affinity , Electronegativity.

Description : Define the following : Atomic Radii , Ionization Energy , Electron Affinity , Electronegativity.

Last Answer : Ans :(1) Atomic Radii : An atom does not have strictly defined boundaries so it is impossible to determine the exact radius of an atom but theoretically it is defined as half the distance between the ... in Period : It increases from left to right in a period due to increase in nuclear charge.

How degree of ionization effects the strength of an acid or base according to Arrhenius concept?

Description : How degree of ionization effects the strength of an acid or base according to Arrhenius concept?

Last Answer : Ans: An acid or base which will ionize completely, having high degree of ionization, will give more H+ or –OH ions. And will be a strong acid or base.

The difference in the osmotic pressures of one molar solutions of different compounds in a given solvent at a given temperature results from? w) Different values for R x) Different values for Avogadro's number y) Ionization or dissociation z) None of the above

Description : The difference in the osmotic pressures of one molar solutions of different compounds in a given solvent at a given temperature results from? w) Different values for R x) Different values for Avogadro's number y) Ionization or dissociation z) None of the above

Last Answer : ANSWER: Y -- IONIZATION OR DISSOCIATION 

Within a given period of the periodic table, the element with the lowest ionization energy is: w) transition metal x) alkali metal y) halogen z) noble gas

Description : Within a given period of the periodic table, the element with the lowest ionization energy is: w) transition metal x) alkali metal y) halogen z) noble gas

Last Answer : ANSWER: X -- ALKALI METAL

A cobalt chloride solution soaked into a piece of cotton can be used as an indicator for changes in humidity levels. Pink indicates a high-humidity environment and blue a low-humidity environment. What are these color changes caused by: w) The ionization and reduction of the cobalt plus two slash cobalt plus three couple. x) The vaporization and redeposition of cobalt chloride. y) The loss and readsorption of the cobalt's waters of hydration. z) This is an illustration of the Schrodinger principle.

Description : A cobalt chloride solution soaked into a piece of cotton can be used as an indicator for changes in humidity levels. Pink indicates a high-humidity environment and blue a low-humidity environment. What ... the cobalt's waters of hydration. z) This is an illustration of the Schrodinger principle.  

Last Answer : ANSWER: Y -- THE LOSS AND READSORPTION OF THE COBALT'S WATERS OF HYDRATION.

Which of the following elements has the highest first ionization energy? w) Helium x) Neon y) Fluorine z) Argon

Description : Which of the following elements has the highest first ionization energy? w) Helium x) Neon y) Fluorine z) Argon

Last Answer : ANSWER: W -- HELIUM

If the first ionization energy of magnesium is 176 kilocalories per mole, one would expect the second ionization energy t be approximately: w) 350 kilocalories per mole x) 1,760 kilocalories per mole y) 200 kilocalories per mole z) 20 kilocalories per mole

Description : If the first ionization energy of magnesium is 176 kilocalories per mole, one would expect the second ionization energy t be approximately: w) 350 kilocalories per mole x) 1,760 kilocalories per mole y) 200 kilocalories per mole z) 20 kilocalories per mole

Last Answer : ANSWER: W -- 350 KILOCALORIES PER MOLE 

Which of the following would have the largest THIR ionization energy? Is it: w) Boron x) Carbon y) Nitrogen z) Magnesium

Description : Which of the following would have the largest THIR ionization energy? Is it: w) Boron x) Carbon y) Nitrogen z) Magnesium

Last Answer : ANSWER: Z -- MAGNESIUM

As one goes across a period in the periodic table, the ionization energy generally increases for one of the following reasons. Is it because of the increasing w) atomic radius x) melting point y) nuclear charge z) density

Description : As one goes across a period in the periodic table, the ionization energy generally increases for one of the following reasons. Is it because of the increasing w) atomic radius x) melting point y) nuclear charge z) density

Last Answer : ANSWER: Y -- NUCLEAR CHARGE

The noble gases have low boiling points because: w) their ionization potentials are very low x) only weak Van der Waals forces hold the atoms together y) they are produced by the fractional distillation of liquid air z) they have eight electrons in the outer shell

Description : The noble gases have low boiling points because: w) their ionization potentials are very low x) only weak Van der Waals forces hold the atoms together y) they are produced by the fractional distillation of liquid air z) they have eight electrons in the outer shell

Last Answer : ANSWER: X -- ONLY WEAK VAN DER WAALS FORCES HOLD THE ATOMS TOGETHER

Which among the following is not a characteristic of transition metals? (1) Tendency to gain electrons (2) Low electronegativity (3) Low ionization energy (4) Malleability

Description : Which among the following is not a characteristic of transition metals? (1) Tendency to gain electrons (2) Low electronegativity (3) Low ionization energy (4) Malleability 

Last Answer : Tendency to gain electrons

Assertion :- Metallic character increases on going down the group Reason :- I.E. decreases on going down the group

Description : Assertion :- Metallic character increases on going down the group Reason :- I.E. decreases on going down the group

Last Answer : Assertion :- Metallic character increases on going down the group Reason :- I.E. decreases on going ... . D. If both Assertion & Reason are false

Choose the correct statement. (a) Electronegativity increases down a group (b) Electronegativity decreases down a group (c) Electronegativity decreases from left to right along a period (d) Electronegativity changes along a group, but remains constant along a period

Description : Choose the correct statement. (a) Electronegativity increases down a group (b) Electronegativity decreases down a group (c) Electronegativity decreases from left to right along a period (d) Electronegativity changes along a group, but remains constant along a period

Last Answer : Ans:(b)