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Questions on Atoms, Orbitals and Electron Configurations

To test whether you know all that you need to know you must try to answer these questions before you look at the answers!
You may wish to refer to a periodic table when answering the following questions.

Atoms

1.  How many electrons are there in N3- ?
2.  What is the atomic mass unit for bromine ?
3.  How many protons and neutons are there in each of the following : 1H, 2H, 12C, 16O, 35Cl and 37Cl ?

Answers ?

Orbitals

1.  Which quantum number defines the energy level of an orbital for (a) the hydrogen atom and (b) other atoms ?
2.  What are the quantum numbers that describe a 3p orbital ?
3.  How many occupied valence orbitals are there in Cl and I ?
4.  What are the quantum numbers for an electron in a 3s orbital ?

Answers ?

Electron Configurations

Use the information given in the box below when answering the next three questions:

(a)  [Ar] (d)  1s22s22p63s23px23py1
(b)  1s22s22p63s1 (e)  1s22s22p63s23px13py13pz1
(c)  1s22s22p63p1

1.  Which of the electron configurations above best describes the ground state electron configuration of Cl-?
2.  Which of the electron configurations above is possible for the ground state of P?
3.  Which of the electron configurations above describes an excited state of Mg+?

4.  Is the following electron configuration consistent with Hund's rule of maximum multiplicity?

5.  Is the following electron configuration consistent with Pauli's exclusion principle? 6.  What is the orbital energy diagram that best describes the core electron configuration of Si?

7.  What is the orbital energy diagram that best describes the valence electron configuration of O?

Answers ?