University:
Glendale Community College
Course:
CHM152 General Chemistry II
Academic year:

2020
Views:

405

Pages:

2
Author:

siuleteja85

Electron Configurations Worksheet For atoms, the number of electrons = number of protons because atoms are neutral. Remember you are filling in ALL the electrons, not just valence, but ALL. The order of filling in electrons in the subshells is 1s 2s 2p 3s 3p 4s s subshells have only 1 orbital, 2 electrons per orbital = 2 electrons max p subshells have 3 orbitals, 2 electrons per orbital = 6 electrons max You fill the electrons into the subshells until you reach the correct number of electrons. Write electron configurations for: He ______________________________________________ Li______________________________________________ Be______________________________________________ O______________________________________________ Cl______________________________________________ K______________________________________________ For ions you must add or subtract the number of electrons from the atom which account for the charge. For positive ions, they have LOST electrons, so there are LESS electrons than the atom. For negative ions, they have GAINED electrons, so there are MORE electrons than the atoms. Same rules apply. Write electron configurations for the following. What noble gas are they isoelectronic with? Li+______________________________________________ N3-______________________________________________ Be2+______________________________________________ S2-______________________________________________ Al3+______________________________________________ K+______________________________________________ Answers: Element # of Electrons in Element Electron Configuration He 2 1s2 Li 3 1s22s1 Be 4 1s22s2 O 8 1s22s22p4 Cl 17 1s22s22p63s23p5 K 19 1s22s22p63s23p64s1 Isoelectronic with Electron Configuration Element Charge TOTAL # of Electrons in Ion Li+ One less e- so 3-1= 2 2 He 1s2 N3- 3 more e- so 7+3=10 10 Ne 1s22s22p6 Be+2 2 less e- so 4-2= 2 2 He 1s2 S-2 2 more e- so 16 + 2 = 18 18 Ar 1s22s22p63s23p6 Al3+ 3 less e- so 13-3=10 10 Ne 1s22s22p6 K+ One less e- so 19-1=18 18 Ar 1s22s22p63s23p6