1.	Which statement about the numbers of protons, electrons and neutrons in an atom is always correct?
A.	The number of neutrons minus the number of electrons is zero.
B.	The number of protons plus the number of neutrons equals the number of electrons.
C.	The number of protons equals the number of electrons.
D.	The number of neutrons equals the number of protons.
(Total 1 mark)

2.	(a)	Explain why the relative atomic mass of argon is greater than the relative atomic mass of potassium, even though the atomic number of potassium is greater than the atomic number of argon.
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(1)
 
(b)	Deduce the numbers of protons and electrons in the K+ ion.
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(1)
 
(c)	Deduce the electron arrangement for the K+ ion.
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(1)
(Total 3 marks)

3.	Identify a radioactive isotope of carbon and state one of its uses.
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(Total 1 mark)

4.	Which quantities are the same for all atoms of chlorine?
I.	Number of protons
II.	Number of neutrons
III.	Number of electrons
A.	I and II only
B.	I and III only
C.	II and III only
D.	I, II and III
(Total 1 mark)

5.	Which statements about the isotopes of chlorine,  and , are correct?
I.	They have the same chemical properties.
II.	They have the same atomic number.
III.	They have the same physical properties.
A.	I and II only
B.	I and III only
C.	II and III only
D.	I, II and III
(Total 1 mark)

6.	Which of the following is an isotope of 
A.	
B.	
C.	
D.	
(Total 1 mark)

7.	How many electrons does the ion  contain?
A.	12
B.	15
C.	16
D.	18
(Total 1 mark)

8.	Which statement about the species 63Cu2+ and 65Cu+ is correct?
A.	Both species have the same number of protons.
B.	Both species have the same number of electrons.
C.	Both species have the same number of neutrons.
D.	Both species have the same electron arrangement.
(Total 1 mark)

9.	Which statement about the isotopes of an element is correct?
A.	They have the same mass number.
B.	They have a different atomic number.
C.	They have the same chemical properties.
D.	They are located in different places in the periodic table.
(Total 1 mark)

10.	How many protons, neutrons and electrons are present in each atom of 31P?

	Protons	Neutrons	Electrons	
A.	16	15	16	
B.	15	16	15	
C.	15	31	15	
D.	16	31	16	
(Total 1 mark)

11.	What is the atomic number of a neutral atom which has 51 neutrons and 40 electrons?
A.	40
B.	51
C.	91
D.	131
(Total 1 mark)

12.	Which is the correct definition of the mass number of an atom?
A.	The total mass of neutrons and protons in the nucleus of the atom
B.	The total mass of neutrons, protons and electrons in the atom
C.	The number of protons in the nucleus of the atom
D.	The total number of neutrons and protons in the nucleus of the atom
(Total 1 mark)

13.	The table below shows the number of protons, neutrons and electrons present in five species.

Species	Number of protons	Number of neutrons	Number of electrons	
X	6	8	6	
Y	7	7	7	
Z	7	7	8	
W	8	8	8	
Q	8	10	8	
	Which two species are isotopes of the same element?
A.	X and W
B.	Y and Z
C.	Z and W
D.	W and Q
(Total 1 mark)

14.	Which species have the same number of electrons?
I.	S2–
II.	Cl–
III.	Ne
A.	I and II only
B.	I and III only
C.	II and III only
D.	I, II and III
(Total 1 mark)

15.	Which species has 54 electrons and 52 protons?
A.	
B.	
C.	
D.	
(Total 1 mark)

16.	In the emission spectrum of hydrogen, which electronic transition would produce a line in the visible region of the electromagnetic spectrum?
A.	n = 2 →n = 1
B.	n = 3 → n = 2
C.	n = 2 → n = 3
D.	n = ∞ → n = 1
(Total 1 mark)

17.	Which describes the visible emission spectrum of hydrogen?
A.	A series of lines converging at longer wavelength
B.	A series of regularly spaced lines
C.	A series of lines converging at lower energy
D.	A series of lines converging at higher frequency
(Total 1 mark)

18.	What is the electron arrangement of the Mg2+ ion?
A.	2,2
B.	2,8
C.	2,8,2
D.	2,8,8
(Total 1 mark)

19.	Draw and label an energy level diagram for the hydrogen atom. In your diagram show how the series of lines in the ultraviolet and visible regions of its emission spectrum are produced, clearly labelling each series.

(Total 4 marks)

20.	Which is correct for the following regions of the electromagnetic spectrum?

	Ultraviolet (UV)	Infrared (IR)	
A.	high energy	short wavelength	low energy	low frequency	
B.	high energy	low frequency	low energy	long wavelength	
C.	high frequency	short wavelength	high energy	long wavelength	
D.	high frequency	long wavelength	low frequency	low energy	
(Total 1 mark)

21.	Describe the emission spectrum of hydrogen. Outline how this spectrum is related to the energy levels in the hydrogen atom.
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(Total 3 marks)

22.	(a)	List the following types of electromagnetic radiation in order of increasing wavelength (shortest first).
I.	Yellow light
II.	Red light
III.	Infrared radiation
IV.	Ultraviolet radiation
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(1)
 
(b)	Distinguish between a continuous spectrum and a line spectrum.
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(1)

(c)	The thinning of the ozone layer increases the amount of UV-B radiation that reaches the Earth’s surface.
Type of Radiation	Wavelength / nm	
UV-A 	320–380	
UV-B	290–320	
	Based on the information in the table above explain why UV-B rays are more dangerous than UV-A.
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(3)
(Total 5 marks)

23.	What is the electron configuration of vanadium?
A.	1s22s22p63s23p63d24s3
B.	1s22s22p63s23p63d34s2
C.	1s22s22p63s23p63d44s1
D.	1s22s22p63s23p63d5
(Total 1 mark)

24.	(a)	Explain why the relative atomic mass of cobalt is greater than the relative atomic mass of nickel, even though the atomic number of nickel is greater than the atomic number of cobalt.
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(1)

(b)	Deduce the numbers of protons and electrons in the ion Co2+.
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(1)
 
(c)	Deduce the electron configuration for the ion Co2+.
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(1)
 
(d)	Identify a radioactive isotope of cobalt and state one of its uses.
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(1)
(Total 4 marks)

25.	Values for the successive ionization energies for an unknown element are given in the table below.

First ionization energy / kJ mol–1	Second ionization energy / kJ mol–1	Third ionization energy / kJ mol–1	Fourth ionization energy / kJ mol–1	
420	3600	4400	5900	
	In which group of the periodic table would the unknown element be found?
A.	1
B.	2
C.	3
D.	4
(Total 1 mark)

26.	The electron configuration of chromium can be expressed as [Ar]4sx3dy.
(i)	Explain what the square brackets around argon, [Ar], represent.
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(1)
 
(ii)	State the values of x and y.
x: ..................................................................................................................................
y: ..................................................................................................................................
(1)
 
(iii)	Annotate the diagram below showing the 4s and 3d orbitals for a chromium atom using an arrow,  and , to represent a spinning electron.

4s				3d			
(1)
(Total 3 marks)

27.	The graph represents the energy needed to remove nine electrons, one at a time, from an atom of an element. Not all of the electrons have been removed.
		
	Which element could this be?
A.	C
B.	Si
C.	P
D.	S
(Total 1 mark)

28.	An ion has the electron configuration 1s2 2s2 2p6 3s2 3p6 3d10. Which ion could it be?
A.	Ni2+
B.	Cu+
C.	Cu2+
D.	Co3+
(Total 1 mark)

29.	What is the electron configuration of Fe3+?
A.	[Ar]4s23d6
B.	[Ar]3d5
C.	[Ar]4s23d5
D.	[Ar]4s23d3
(Total 1 mark)

30.	The graph below represents the successive ionization energies of sodium. The vertical axis plots log (ionization energy) instead of ionization energy to allow the data to be represented without using an unreasonably long vertical axis.

	State the full electron configuration of sodium and explain how the successive ionization energy data for sodium are related to its electron configuration.
(Total 4 marks)

31.	The graph below shows the first four ionization energies of four elements A, B, C and D (the letters are not their chemical symbols). Which element is magnesium?

(Total 1 mark)

32.	Magnesium is the eighth most abundant element in the earth’s crust. The successive ionization energies of the element are shown below.

(i)	Define the term first ionization energy and state the equation for the first ionization of magnesium.
(3)
 
(ii)	Explain the general increase in successive ionization energies of the element.
(2)
 
(iii)	Explain the large increase between the tenth and eleventh ionization energies.
(3)
(Total 8 marks)

33.	Which species possesses only two unpaired electrons?
A.	Zn
B.	Mg
C.	Ti2+
D.	Fe2+
(Total 1 mark)

34.	Draw the Lewis structures, state the shape and predict the bond angles for the following species.
(i)	PCl3
(3)
 
(ii)	NH2–
(3)
 
(iii)	XeF4
(3)
(Total 9 marks)

35.	The graph of the first ionization energy plotted against atomic number for the first twenty elements shows periodicity.

(i)	Define the term first ionization energy and state what is meant by the term periodicity.
(2)
 
(ii)	Explain how information from this graph provides evidence for the existence of main energy levels and sub-levels within atoms.
(4)
 
(iii)	State what is meant by the term second ionization energy.
(1)
 
(iv)	Sketch and explain the shape of the graph obtained for the successive ionization energies of potassium using a logarithmic scale for ionization energy on the y-axis against number of electrons removed on the x-axis.
(4)
(Total 11 marks)

36.	What is the order of increasing energy of the orbitals within a single energy level?
A.	d < s < f < p
B.	s < p < d < f
C.	p < s < f < d
D.	f < d < p < s
(Total 1 mark)

37.	What is the electron configuration of the Cr2+ ion?
A.	[Ar] 3d5 4s1
B.	[Ar] 3d3 4s1
C.	[Ar] 3d6 4s1
D.	[Ar] 3d4 4s0
(Total 1 mark)

38.	(a)	(i)	Draw the shape of the pz orbital using the coordinates shown.
		
(1)

(ii)	State the electron configuration of Fe3+.
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(1)
 
(iii)	Define the term ligand.
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(1)
 
(iv)	Explain why the complex [Fe(H2O)6]3+ is coloured.
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(3)
 
(v)	The element selenium (Z = 34) has electrons in the 4s, 3d and 4p orbitals. Draw an orbital box diagram (arrow-in-box notation) to represent these electrons.

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(1)
(Total 7 marks)

39.	Between which ionization energies of boron will there be the greatest difference?
A.	Between 1st and 2nd ionization energies
B.	Between 2nd and 3rd ionization energies
C.	Between 3rd and 4th ionization energies
D.	Between 4th and 5th ionization energies
(Total 1 mark)

40.	What is the electron configuration for the copper(I) ion, (Z = 29)?
A.	[Ar]4s23d9
B.	[Ar]4s13d10
C.	[Ar]4s13d9
D.	[Ar]3d10
(Total 1 mark)