158. Which of the following statements is(are) true? a. F has a larger first ionization energy than does Li. b. Cations are larger than their parent atoms c. The removal of the first electron from a lithium atom (electron configuration is 1s22s1) is exothermic-that is, removing this electron gives off energy. d. The He atom is larger than the H ion. e. The Al atom is smaller than the Li atom.
Solution
a) F has a larger first ionisation energy than Li
Ionisation energy is the energy required to remove an electron. Flourine needs 1 electron to attain octet. While lithium needs to lose 1 elevelec to gain Noble gas configuration. Hence it is easier for lithium to lose an electron and ionisation energy of lithium is less than that of fluorine.
Generally anions are larger than parent atoms because the electron electron repulsion is more in them due to addition of an electron.
Removal of an electron is always endothermic because it requires breaking of protons electron attractive forces.
H+ ions are smaller than H. Hence He is larger than H+ ions.
Al atom is larger than Li atom because the number of electrons in Al atom is more.
.
158- Which of the following statements is(are) true- a- F has a larger.docx
1. 158. Which of the following statements is(are) true? a. F has a larger first ionization energy than
does Li. b. Cations are larger than their parent atoms c. The removal of the first electron from a
lithium atom (electron configuration is 1s22s1) is exothermic-that is, removing this electron
gives off energy. d. The He atom is larger than the H ion. e. The Al atom is smaller than the Li
atom.
Solution
a) F has a larger first ionisation energy than Li
Ionisation energy is the energy required to remove an electron. Flourine needs 1 electron to attain
octet. While lithium needs to lose 1 elevelec to gain Noble gas configuration. Hence it is easier
for lithium to lose an electron and ionisation energy of lithium is less than that of fluorine.
Generally anions are larger than parent atoms because the electron electron repulsion is more in
them due to addition of an electron.
Removal of an electron is always endothermic because it requires breaking of protons electron
attractive forces.
H+ ions are smaller than H. Hence He is larger than H+ ions.
Al atom is larger than Li atom because the number of electrons in Al atom is more.
