Section A

 

For each of the questions only ONE of the lettered responses (A-D) is correct.

 

Select the correct response in each case and mark its code letter by connecting the dots as illustrated on the answer sheet.

 

1        Which one of the following is the electronic configuration of a titanium atom?

 

A 1s22s22p63s23p64s24p2

@B 1s22s22p63s23p63d24s2

C 1s22s22p63s23p63d34s1

D 1s22s22p63s23p64s24p2

 

2     Which one of the following is the electronic configuration of the bromine atom?

 

A 1s22s22p63s23p63d104s14p6

B 1s22s22p6 3s23p63d104s24p7

@C 1s22s22p63s23p63d104s24p5

D 1s22s22p63s23p63d104s24p6

 

 

4     The nucleus of 2311Na contains

 

A   23 protons and 11 electrons

B  23 protons and 11 neutrons

@C  11 protons and 12neutrons 

D  11 protons and 12electrons

 

5     The first ionisation energy for carbon is greater than it is for sodium. One of the factors responsible is that the                

 

A  nuclear charge on carbon is greater

B  outer quantum shell is further from the nucleus in carbon atoms than in sodium atoms

C  number of electrons in the outer quantum shell of carbon is greater than in sodium

@D  shielding provided by the inner quantum shells in sodium is greater

                                 

 

                                                  

                                               

Section B

 

1           The first. seven types of orbital permitted for any atom are, in random order, 2s, 3p, 4s, 3d, ls, 2p, 3s.

 

If the atom is Ca, write down the orbitals in order of increasing energy (from left to right) and give the number of electrons in each orbital.   

                                                           

                                                                                                                                                                                               

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2. (a)  Sketch a line spectrum of hydrogen (Lyman series only, wavelength increasing from left to right).

 

 

 

 

 

 

                                                                                                                                                                            [2]

 

  (b)         The charge on the oxygen nucleus is eight times that on the hydrogen nucleus and yet the first ionization energies of hydrogen and oxygen are almost identical (~1300 kJ mol-1).

Suggest reasons for this.

                                                                                                                                                                                [2]