Exam-style questions 1 Which of the following contains 50 neutrons? A
50 23 V
B
89 + 39 Y
C
91 + 40 Zr
D
86 + 37 Rb
79 − 35 Br
D
40 2+ 20 Ca
2 Which of the following has more electrons than neutrons? A
9 2+ 4 Be
B
31 3− 15 P
C
3 Rhenium has two naturally occurring isotopes, 185Re and 187Re. The relative atomic mass of rhenium is 186.2. What are the natural abundances of these isotopes? A B C D
40% 185Re and 60% 187Re 60% 185Re and 40% 187Re 12% 185Re and 88% 187Re 88% 185Re and 12% 187Re
4 Which of the following electron transitions in the hydrogen atom will be of highest energy? A n=8 → n=4 B n=7 → n=2
C n=9 → n=3 D n=6 → n=2
HL 5 Within any main energy level the correct sequence, when the sub-energy levels (subshells) are arranged in order of
increasing energy, is: A s B d
p s
f f
d p
C s D s
p d
d p
f f
HL 6 Which of the following electron configurations is not correct?
A Mg: 1s22s22p63s2 B Cu: 1s22s22p63s23p64s23d9
C Ge: 1s22s22p63s23p63d104s24p2 D Br: 1s22s22p63s23p64s23d104p5
−34 14 HL 7 Planck’s constant is 6.63 × 10 J s. The energy of a photon of light with frequency 5.00 × 10 Hz is:
A 7.54 × 1047 J B 1.33 × 10−48 J
C 3.32 × 10−19 J D 1.33 × 10−20 J
HL 8 Which of the following does not have three unpaired electrons?
A P
B V
C Mn3+
D Ni3+
HL 9 In which of the following does the second element have a lower first ionisation energy than the first?
A B C D
80
Si Na Be Ar
C Mg B Ne