Question

9. Explain why ionization energy decreases as you move down the noble gases from Helium to argon. 10. Sodium atoms are much larger than chlorine atoms, but sodium ions are much smaller than chloride ions. Why? 11. Compounds have been made from Xenon and Krypton, but not from other noble gases. Give a reason why you think this is true. 12. Based on energy changes involved in forming ions, why does Copper form both Cut and Cu2 ions but Sodium forms Nations but not Nations? 13. Write the expected electron configurations for: a) the element with one unpaired 5p electron that can form an ionic compound with sodium b) the "as yet undiscovered" alkaline earth metal after radium c) the noble gas with electrons occupying 4f orbitals 14. Atoms with unpaired electrons are attracted by magnetic fields and thus are said to exhibit “paramagnetism". The degree to which this effect is observed is directly related to the number of unpaired electrons present in the atom. For the following elements, which of these would be expected to be paramagnetic. For each paramagnetic atom, how many unpaired electrons are present? L, N, NI, Te, Ba, Hg 15. Give three ions that are isoelectronic with Ar. Place these ions in order of increasing size. 16. For each of these pairs of elements (C and N), (Ar and Br), pick the atom with a) the most favorable (largest negative value) electron affinity b) highest ionization energy largest size EXPLAIN why in each case.

Answer 1

* Tonisation energy decreases down the group 9. of noble gas - helium to argon. This is due to the size of arogen is increased as it has bouber most ard orbit. larger the size causes lower effective nuclear charge of outer most electron. Hezis2 Nez 15² 2s 2 2p6 Bir 2 15² 252 2p8 38² 3p6

10. Na 2152 28% 2p6 38! de 150 25 apr 38² 305. Now, todos more Sodnim and chlorine home same outermost orbit-3. In case of chlorine there is for more proton in nuclens than Na. so the effective nuclear charge will is greater and contract the size & chlorine. so sodium is larger thom a. Natz 15² 25² 2p6 g Cl2 26² 2s ² 2p 635²3p6. when they ionised then na loses one eleison and reactes noble gara configuration. And to the positive charge means more proton in welcay Causes more confortion and shortend the size. In case of a there is a negetive charge a which increases the size of atoon chiroine due to the election - elechon repulsion.

M e and ks are higher noble gors. Due to the large size and small ionisation energy they con form compound with high electronegtive atong like ok. 12 Cuz 1822528635²306 45 32 to cut a 18 25 28 35 366 3d 10 Cu 2+2 18 25 2 206 35² 3p6 249 From the electronic configuzation to can be established that the pland +2 charge of car where as na 2 15² 253 qp 3s' Natz 18228²206 Na2t As 252 25(X) Na 2t is not possible due to! the high energy required to remone on the electron from stable 25 266 Configuration. Nat can form because of sooble garo stability