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Essential Chemistry for IGCSE - Structure And Bonding (Section 1)

1
In a dot and cross diagram of methane (CH4), how many electrons are shown surrounding the carbon atom?
Answer
(D)
8
2
How many electrons are involved in a single covalent bond?
Answer
(B)
2
3
What happens to the electrons when a sodium atom forms an ion?
Answer
(B)
It loses one electron.
4
Which of the following statements is true concerning the structure of graphite?
Answer
(C)
It contains delocalized electrons.
5
Which of the following statements about intermolecular forces is/are correct?
Answer
B
C
D
6
Which of the following is a good conductor of electricity?
Answer
(B)
Graphite
7
Which of the following pairs of atoms would most likely form a covalent bond?
Answer
(C)
Hydrogen and Oxygen
8
What is the electronic structure of a sodium atom?
Answer
(A)
2, 8, 1
9
What type of bonding is present within the layers of graphite?
Answer
(C)
Covalent
10
Which of the following is the correct dot and cross diagram for water?
Answer
(A)
H:O:H
11
What type of bonding is present in graphite?
Answer
(C)
Covalent bonding and weak intermolecular forces
12
Which of the following is a use of silicon dioxide (SiO2)?
Answer
(D)
As a component of glass.
13
Which two properties are usually characteristic of substances that are held together by intermolecular forces?
Answer
(C)
Low melting point and high volatility.
14
What are the key differences between the structure of Diamond and Graphite?
Answer
B
C
D
15
What type of force exists between molecules in a simple molecular substance?
Answer
(D)
Intermolecular forces
16
Why does graphite feel slippery?
Answer
(A)
Because the layers slide over each other due to weak forces.
17
What is the electronic structure of oxygen?
Answer
(A)
2, 6
18
Which statement explains why graphite is a good conductor of electricity?
Answer
(B)
It has delocalized electrons.
19
What type of bond is broken when an ionic compound dissolves in water?
Answer
(C)
Metallic bond
20
Which of the following statements is/are true about covalent bonds?
Answer
A
B
21
Which of the following is a characteristic of a substance that exists as simple molecules?
Answer
(C)
It has weak intermolecular forces.
22
What is the name given to a group of atoms that are covalently bonded together?
Answer
(B)
Molecule
23
Which of the following is a reason why graphite is used as a lubricant?
Answer
(C)
The layers of carbon atoms can slide over each other.
24
Which of the following is a property of covalent compounds?
Answer
(C)
Low melting point.
25
Which of the following correctly describes the bonding in a water molecule (H2O)?
Answer
(C)
Covalent bonds
26
What is the maximum number of electrons that can occupy the outermost shell of an atom (octet rule)?
Answer
(C)
8
27
Which of the following statements about the bonding in methane (CH4) is/are correct?
Answer
B
C
28
Which of the following elements would most likely form an ionic bond with potassium (K)?
Answer
(B)
Chlorine (Cl)
29
What is the charge of a sodium ion?
Answer
(C)
+1
30
Which of the following compounds is *not* an example of a simple covalent molecule?
Answer
(C)
Sodium chloride (NaCl)
31
Why are covalent compounds generally poor conductors of electricity?
Answer
(D)
Both A and C are correct.
32
What type of bond is formed when non-metal atoms share electrons?
Answer
(B)
Covalent bond
33
Which of the following statements regarding melting points are true?
Answer
A
B
34
What is formed when an atom gains an electron?
Answer
(B)
A negative ion
35
Which substance has the lowest melting point?
Answer
(C)
Water
36
Which of the following is a property of a molecule with a double bond?
Answer
B
C
37
Which of the following statements is/are correct regarding the properties of substances with giant covalent structures?
Answer
B
C
38
Which of the following best describes the structure of a giant covalent lattice?
Answer
(A)
A three-dimensional network of atoms held together by covalent bonds.
39
Which of the following statements are correct about ionic compounds?
Answer
A
C
D
40
Which of the following is NOT a property associated with ionic compounds?
Answer
(C)
Exist as molecules
41
Which of the following statements are TRUE about the structure of NaCl?
Answer
B
C
D
42
Which of the following is a property of ionic compounds?
Answer
(B)
High melting points
43
In the formation of an ionic bond, what happens to electrons?
Answer
(B)
They are transferred from one atom to another.
44
Why are simple molecular substances gases or liquids at room temperature?
Answer
(C)
They have weak intermolecular forces.
45
Which of the following statements is correct regarding the melting and boiling points of simple molecular substances?
Answer
(B)
They have low melting and boiling points.
46
Which of the following is a difference between an ionic compound and a covalent compound?
Answer
C
D
47
Which of the following factors explains why ionic compounds conduct electricity when dissolved in water?
Answer
(B)
The ions are free to move in the solution.
48
Which of the following is a characteristic that distinguishes a covalent compound from an ionic compound?
Answer
(B)
Covalent compounds are poor conductors of electricity.
49
Which of the following would you expect to have the lowest melting point?
Answer
(C)
Water
50
What is the charge on a chloride ion?
Answer
(B)
-1