Name: Answers Teacher: Mr. Hung
Instructions: Write answers in the right-hand column. Score: ______
Section A— Multiple choice (20 marks) 1 mark each
1 / Which of the following particles are used in determining the position of an element within the periodic table?A protons number
B neutrons number
C mass number
D the size of the atom / A / 1
2 / Sodium has 11 electrons. When in its ground state, its electron configuration is:
A 11
B 2,8,1
C 2,9
D 10,1 / B / 1
3 / Which of the following statements about elements in group 8 is CORRECT?
A They form ionic compounds easily.
B All atoms in this group have 8 electrons in their outermost shell.
C Group 8 is known as the halogens.
D All group 8 atoms form diatomic molecules like O2. / B / 1
4 / An atom has an electron configuration of 2,8,8,1. What group would it be in?
A 1
B 4
C 7
D 5 / a / 1
5 / Covalent bonding occurs between:
A metal atoms and other metal atoms
B metal and non-metal atoms
C non-metal atoms and other non-metal atoms
D lattices / c / 1
6 / Aluminium is in group 3. Use this information to determine the most likely charge of beryllium ions.
A +3
B -3
C +5
D -5 / a / 1
7 / Sulphur has an electron configuration 2,8,6. Use this information to determine the most likely charge of sulphide ions.
A +6
B -6
C +2
D -2 / d / 1
8 / Which of the diatomic molecules has a triple bond?
A Chlorine gas
B Oxygen gas
C Nitrogen gas
D Hydrogen gas / C / 1
9 / Which is the element found in the pencil lead?
A Carbon
B Calcium
C Lead
D Silver / A / 1
10 / Nitrogen N is in period 2, group 5. Which of the following elements would have properties most similar to nitrogen?
A oxygen O (period 2, group 6)
B neon Ne (period 2, group 8)
C sodium (Na) because its symbol also starts with N
D phosphorus P (period 3, group 5) / D / 1
11 / Which element is liquid at room temperature?
A Sulphur
B Iodine
C Bromine
D Argon / C / 1
12 / Which is the least reactive metal?
A Copper
B Silver
C Sodium
D Aluminium / B / 1
13 / Which is the best term to describe the following reaction?
CaCO3(s) ® CaO(s) + CO2(g)
A combination reaction
B metal displacement reaction
C precipitation reaction
D decomposition reaction / D / 1
14 / Explain why crushing solid reactants helps to increase the rate of reaction.
A It exposes more of the solid reactant to the other reactants so there can be more reactions occurring at any one time.
B It weakens the chemical bonds in the solid so that it is easier for the reaction to occur.
C It helps the solid to dissolve.
D It gives more energy to the solid / A / 1
15 / Which is the same name as a radical?
A cation
B anion
C polyatomic ion
D diatomic ion / C / 1
16 / Which are properties of metals in general?
A Good conductor of heat and bad conductor of electricity
B Good conductor of heat and good conductor of electricity
C Bad conductor of heat and bad conductor of electricity
D Bad conductor of heat and good conductor of electricity / B / 1
17 / Which is the correct name for Zn3(PO4)2?
A Zinc Phosphoride
B Zinc Phosphate
C Zinc Phosphorous
D Zincide Phosphate / B / 1
18 / How many atoms are there in Zn3(PO4)2?
A 9 B 10 C 11 D 13 / D / 1
19 / What is the use of flame test?
A To test for anions
B To find out whether a chemical is an ionic or a covalent compound
C To test for cations
D To test whether a compound consists of radical / C / 1
20 / An alloy is best described as:
A a country cooperating with another country
B a pure metal
C a mixture of a metal and an impurity added to improve it in some way
D a method of using electricity to extract a pure metal. / C / 1
Section B— Short answer (50 marks)
a a proton
b a neutron
c an electron
d nucleus
e atom
f ionic compound / a a proton = + or +1
b a neutron = 0 or neutral
c an electron = - or -1
d nucleus = + (cannot specify any number)
e atom = 0 or neutral
f 0 or neutral / 6
2 / Magnesium has an atomic number of13.Error! sorry from Mr. Hung
Aluminium 13 and Magnesium 12
a State how many protons would be in the nuclei of its atoms.
b State how many electrons would be in each of its atoms.
c State the electron configuration of its atoms when in their ground state.
d Draw a electron shell diagram showing the number of protons, neutrons and the electron distribution.
e Predict the most likely charge of magnesium ions.
f The symbol for a sodium ion is Na+. Use this format to state the symbol for a aluminium ion. / a 13 protons (Al) , 12 for Mg
b 13 electrons, 12 for Mg
c 2,8,3, 2,8,2 for Mg
d
e +3
f Al3+ / 7
3 / Use the information given below to state the period and group number of the following elements:
a Calcium (electron configuration 2,8,8,2).
b Lithium (electron configuration 2,1).
c Fluorine (atomic number 9).
d Argon (atomic number 18). / a Calcium: period 4, group 2.
b Lithium: period 2, group 1.
c Fluorine: period 2, group 7.
d Argon: period 3, group 8. / 4
4 / Predict the most likely charges of any ions formed by the following elements.
a Calcium (electron configuration 2,8,8,2)
b Lithium (electron configuration 2,1).
c Fluorine (atomic number 9).
d Argon / a calcium: +2
b lithium: + or +1
c fluorine: - or -1
d argon: no ions formed hence no charge / 4
5 ` / List four ways in which the rate of a reaction may be increased. / higher temperature
more concentrated reactants
agitation (stirring)
larger surface area
use of a catalyst / 4
6 / Define the following terms:
a molecule
b lattice (in ionic compound) / a a chemical with 2 or more atoms bonded together
b lattice = extended 3D structure. / 2
7 / Complete the table about different types of bonding by matching them with the term that best identifies them:
charged atoms, electron “sea”, shared electrons
Bonding / Term
metallic
ionic
covalent
/ metallic = electron ‘sea’
ionic = ‘charged atoms’
covalent = shared electrons / 3
8 / State the group numbers of the following element ‘families’:
a inert gases
b alkali metals
c halogens
d alkaline earths / a inert gases = group 8
b alkali metals = group 1
c halogens = group 7
d alkaline earths = group 2 / 4
9 / Write a balanced formula equation, including states, for the following reaction:
When aqueous solutions of lead(II) nitrate, Pb(NO3)2, and potassium iodide, KI, are mixed, the yellow solid lead(II) iodide, PbI2, forms from the solution, while the soluble salt, potassium nitrate, KNO3, remains in solution.
Name this type of reaction.
/ Pb(NO3)2(aq) + 2KI(aq) ® PbI2(s) + 2KNO3(aq)
Precipitation / Double replacement reaction / 5
10 / The table below shows the symbol or formula of several ions.
Name of ion / Symbol or formula
lithium / Li+
magnesium / Mg2+
chloride / Cl-
aluminium / Al3+
carbonate / CO
sulphide / S2–
nitrate / NO3–
Construct the chemical formula for:
a lithium chloride
b calcium sulphide
c aluminium nitrate
d magnesium carbonate
e aluminium sulphide / a LiCl
b CaS
c Al(NO3)3
d MgCO3
e Al2 S3 / 5
11 / Here is an activity series:
K Na Ca Mg Al Zn Fe Pb Cu Ag Au
a Which metal(s) would be most likely to: [ 7 marks ]
i be found in its natural state Au (gold)
ii be the most active of listed elements K (potassium)
iii be stored in oil K and Na (sodium)
iv be used to make jewellery Cu copper, Ag silver, Au
v burn in air to give a bright light Mg Magnesium
vi displace Silver (Cu or Au) Cu
vii best conductors of electricity Cu and Ag
b What is the meaning Galvanisation? Give an example. [ 2 marks ]
The coating of iron with a more active metal zinc to protect the iron from rusting
c Which of the following reaction takes place? Explain your answer.
[ 2 marks ]
(A) ZnNO3 + Cu ----> Cu(NO3)2 + Zn or
(B) Cu(NO3)2 + Zn -----> Zn(NO3)2 + Cu
as Zinc is a more reactive metal that can displace Copper from copper nitrate, giving solid copper
______
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