CHEMISTRY PROJECT

1. Write the subshell wise electronic configuration
of Ca, K,Zn
Ca - 1S2 2S2 2P6 3S2 3P6 4S2
K - 1s2 2s2 2p6 3s2 3p6 4s1
Zn - 1s2 2s2 2p6 3s2 3p6 3d10 4s2

2. Cr and Cu has a slight change in their electronic
configurations. Why?
Half-filled and completely filled orbital's are more stable. In order to attain stability Cu and Cr slightly have a change in electronic configurations.

3. Write the electronic configurations of Mn ion in
MnO₂,MnCl₂,Mn₂O₃, and Mn₂O7
MnO₂ 1S² 2S² 2P⁶ 3S² 3P⁶ 3d³
MnCl₂ 1S² 2S² 2P⁶ 3S² 3P⁶ 3d⁵
Mn₂O₃ 1S² 2S² 2P⁶ 3S² 3P⁶ 3d⁴
Mn₂O₇ 1S² 2S² 2P⁶ 3S² 3P⁶

4. Why do iron form compounds with two different
valencies ?
Iron is a d block element . the energy difference between the s sub shell of the outermost shell and the d sub shell of the penultimate shell in d block elements is very small. Therefore during compound formation electrons from both these sub shells may be transferred or shared. Hence iron forms compounds with two different valences.

5. Write the increasing order of filling electrons
in the subshells.
1s < 2s < 2p < 3s < 3p <4s <3d <4p <5s Iron is a d block element . The energy difference between the s sub shell of the outermost shell and the d sub shell of the penultimate shell in d block elements is very small. Therefore during compound formation electrons from both these sub shells may be transferred or shared. Hence iron forms compounds with two different valences. <4d <5s <4d <5p <6s <4f <.........

TEST QUESTIONS-1