IONISATION EXAM QUESTIONS WITH
APPROPRIATE ANSWERS
State cand cexplain cthe cgeneral ctrend cin cthe cvalues cof cthe cfirst cionisation cenergies
cof cthe celements cNa cto cAr. c(2) c- cCORRECT✅✅Trend: cfirst cionisation cenergy
cincreases c( c1 c)
Explanation: cThey chave ca chigher cnuclear ccharge cand cstrong cattraction cbetween
couter celectrons cand cprotons cin cnucleus c( c1 c)
State chow, cand cexplain cwhy, cthe cvalues cof cthe cfirst cionisation cenergies cof cthe
celements cAl cand cS cdeviate cfrom cthe cgeneral ctrend. c(5) c- cCORRECT✅✅How cthe
cvalues cdeviate cfrom cthe ctrend: cboth cvalues care ctoo clow c( c1 c) c
Explanation cfor cAl: celectron cremoved cfrom c3p corbital c( c1 c) celectron cis cbetter
cshielded c( c1 c)
Explanation cfor cS: celectron cremoved cfrom c3p celectron cpair c( c1 c) ccauses crepulsion
cbetween cpaired celectron cand creduces cenergy c( c1 c)
Explain cthe cgeneral cincrease cin cthe cvalues cof cthe cfirst cionisation cenergies cof cthe
celements cNa cto cAr c(3) c- cCORRECT✅✅Electrons cinto cthe csame cenergy clevel c( c1
c)
Nuclear ccharge cincreases c(1)
Strong cattraction cbetween cthe cnucleus cand couter celectrons c(1)
In cterms cof celectron csub-levels cinvolved, cexplain cthe cposition cof caluminium cand cthe
cposition cof csulfur cin cthe cdiagram. c(4) c- cCORRECT✅✅Explanation cfor caluminium:
chas ca cthird celectron cin c3p csub cshell c(1) csub cshell cfurther caway cfrom cnucleus c(1)
Explanation cfor csulphur: cHas ca cpair cof celectrons cin c3p corbital c(1) cthis ccauses
crepulsion cbetween celectrons c(1)
Explain cthe cmeaning cof cthe cterm cat cfirst cionisation cof can catom c(1) c-
cCORRECT✅✅Enthalpy cchange/required cwhen can celectron cis cremoved/displaced
cfrom ca cgaseous catom c(1)
Explain cwhy cthe cvalue cof cthe cfirst cionisation cenergy cof cmagnesium cis chigher cthan
cthat cof csodium c(2) c- cCORRECT✅✅Magnesium chas ca chigher cnuclear ccharge
cthan csodium c(1) cand csmaller catom/similar cshielding c(1)
Explain cwhy cthe cvalue cof cthe cfirst cionisation cenergy cof cneon cis chigher cthan cthat cof
csodium c(2) c- cCORRECT✅✅An celectron cis cremoved cfrom ca cshell cof clower
APPROPRIATE ANSWERS
State cand cexplain cthe cgeneral ctrend cin cthe cvalues cof cthe cfirst cionisation cenergies
cof cthe celements cNa cto cAr. c(2) c- cCORRECT✅✅Trend: cfirst cionisation cenergy
cincreases c( c1 c)
Explanation: cThey chave ca chigher cnuclear ccharge cand cstrong cattraction cbetween
couter celectrons cand cprotons cin cnucleus c( c1 c)
State chow, cand cexplain cwhy, cthe cvalues cof cthe cfirst cionisation cenergies cof cthe
celements cAl cand cS cdeviate cfrom cthe cgeneral ctrend. c(5) c- cCORRECT✅✅How cthe
cvalues cdeviate cfrom cthe ctrend: cboth cvalues care ctoo clow c( c1 c) c
Explanation cfor cAl: celectron cremoved cfrom c3p corbital c( c1 c) celectron cis cbetter
cshielded c( c1 c)
Explanation cfor cS: celectron cremoved cfrom c3p celectron cpair c( c1 c) ccauses crepulsion
cbetween cpaired celectron cand creduces cenergy c( c1 c)
Explain cthe cgeneral cincrease cin cthe cvalues cof cthe cfirst cionisation cenergies cof cthe
celements cNa cto cAr c(3) c- cCORRECT✅✅Electrons cinto cthe csame cenergy clevel c( c1
c)
Nuclear ccharge cincreases c(1)
Strong cattraction cbetween cthe cnucleus cand couter celectrons c(1)
In cterms cof celectron csub-levels cinvolved, cexplain cthe cposition cof caluminium cand cthe
cposition cof csulfur cin cthe cdiagram. c(4) c- cCORRECT✅✅Explanation cfor caluminium:
chas ca cthird celectron cin c3p csub cshell c(1) csub cshell cfurther caway cfrom cnucleus c(1)
Explanation cfor csulphur: cHas ca cpair cof celectrons cin c3p corbital c(1) cthis ccauses
crepulsion cbetween celectrons c(1)
Explain cthe cmeaning cof cthe cterm cat cfirst cionisation cof can catom c(1) c-
cCORRECT✅✅Enthalpy cchange/required cwhen can celectron cis cremoved/displaced
cfrom ca cgaseous catom c(1)
Explain cwhy cthe cvalue cof cthe cfirst cionisation cenergy cof cmagnesium cis chigher cthan
cthat cof csodium c(2) c- cCORRECT✅✅Magnesium chas ca chigher cnuclear ccharge
cthan csodium c(1) cand csmaller catom/similar cshielding c(1)
Explain cwhy cthe cvalue cof cthe cfirst cionisation cenergy cof cneon cis chigher cthan cthat cof
csodium c(2) c- cCORRECT✅✅An celectron cis cremoved cfrom ca cshell cof clower
