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Essential Chemistry for IGCSE - Structure And Bonding (Section 5)

1
What type of bond is present in a molecule of carbon dioxide (CO2)?
Answer
(B)
Covalent
2
What is the chemical formula for sodium chloride?
Answer
(B)
NaCl
3
What type of bond would you expect to find in a molecule of hydrogen chloride (HCl)?
Answer
(B)
Covalent
4
In which of the following compounds are covalent bonds present?
Answer
(C)
Methane
5
Which of the following allotropes of carbon conducts electricity?
Answer
(B)
Graphite
6
What is typically the state of simple molecular substances at room temperature?
Answer
(D)
Any of the above
7
Which of the following correctly represents the bonding in magnesium oxide (MgO)?
Answer
(B)
Mg transferring electrons to O.
8
Which statement best describes the formation of an ionic bond?
Answer
(B)
The attraction between a positive ion and a negative ion.
9
In graphite, why are the layers able to slide over each other?
Answer
(C)
Because of weak intermolecular forces.
10
What type of bonding is present in silicon dioxide?
Answer
(B)
Covalent
11
Why is graphite suitable for use as an electrode?
Answer
(B)
Because it has delocalised electrons and conducts electricity.
12
What type of bonding is present in hydrogen molecules (H₂)?
Answer
(C)
Covalent
13
In a covalent bond, the atoms are held together by...
Answer
(A)
Shared electrons
14
Which of the following is formed when an atom gains electrons?
Answer
(B)
An anion
15
Which of the following describes the process of forming an ion?
Answer
(B)
The gain or loss of an electron.
16
Which of the following are not examples of giant covalent structures?
Answer
(D)
Water
17
Which of the following properties is typically associated with simple molecular substances?
Answer
(C)
Low melting point.
18
Which of the following statements correctly describes the octet rule?
Answer
(B)
Atoms tend to gain, lose, or share electrons to achieve a full outer shell of 8 electrons.
19
Which of the following is a property of a simple molecular compound?
Answer
(D)
Low melting point.
20
Which compound conducts electricity when dissolved in water?
Answer
(C)
Sodium chloride
21
What are the two main types of particles present in an ionic compound?
Answer
(B)
Positive ions (cations) and negative ions (anions).
22
In graphite, what type of forces hold the layers together?
Answer
(C)
Van der Waals forces
23
Which of the following compounds is most likely to have high melting and boiling points?
Answer
(B)
Sodium chloride (NaCl)
24
Why does graphite conduct electricity?
Answer
(B)
It contains delocalised electrons
25
What structure does silicon dioxide (SiO2) have?
Answer
(C)
Giant covalent structure
26
Which of the following is not a property of ionic compounds?
Answer
(C)
Dissolve in organic solvents
27
What causes graphite to be soft?
Answer
(C)
Weak intermolecular forces between layers.
28
Why does diamond have a high melting point?
Answer
(B)
It has strong covalent bonds throughout its structure
29
Which of the following is a giant covalent structure?
Answer
(C)
Silicon dioxide
30
What is the electronic configuration of chlorine (atomic number 17)?
Answer
(C)
2, 8, 7
31
What is the maximum number of electrons that can occupy the outermost shell of an atom?
Answer
(C)
8
32
What type of bond is formed between atoms with very different electronegativity values?
Answer
(C)
Ionic bond
33
How many covalent bonds are formed in a molecule of water (H₂O)?
Answer
(B)
Two
34
Which of the following is a feature of simple molecular substances?
Answer
(C)
Low melting and boiling points.
35
What is the formula for the compound formed between sodium and chlorine?
Answer
(C)
NaCl
36
In covalent bonding, what is the role of the nuclei of the atoms?
Answer
(A)
They attract the shared electrons.
37
Why does graphite have a high melting point?
Answer
(A)
Because it is made of strong covalent bonds within the layers
38
What is the state of matter that allows ionic compounds to conduct electricity?
Answer
(D)
Aqueous solution or molten state
39
What is a covalent bond made up of?
Answer
(A)
Shared electrons
40
Why does silicon dioxide have a high melting point?
Answer
(B)
Because it has a giant covalent structure with strong bonds.
41
Which of the following statements is true about the formation of ions?
Answer
(C)
Cations are positively charged, formed by losing electrons.
42
What is the charge on a sodium ion after it forms an ionic bond?
Answer
(A)
+1
43
Which of the following best explains why graphite can conduct electricity?
Answer
(A)
Graphite has delocalised electrons
44
What type of structure does silicon dioxide (SiO2) have?
Answer
(A)
Giant covalent
45
What type of bond results from the transfer of electrons?
Answer
(B)
Ionic
46
What is the electronic configuration of oxygen (atomic number 8)?
Answer
(B)
2, 6
47
What type of structure does carbon dioxide (CO2) have?
Answer
(B)
Simple molecular
48
Which structure describes the bonding in silicon dioxide (SiO2)?
Answer
(C)
Giant covalent structure
49
What type of structure do both diamond and silicon dioxide have?
Answer
(A)
Giant covalent structure
50
Which of the following are correct regarding the properties of graphite?
Answer
A
B