Question 1
What is a chemical bond?
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An attraction holding atoms or ions together
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An attraction acting between separate molecules
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A transfer of electrons between atoms
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A ratio of atoms shown in a formula
Question 2
What happens to electrons in ionic bonding?
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They transfer from one atom to another
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They are shared in pairs between atoms
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They become delocalised through a metal lattice
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They move into the atomic nuclei
Question 3
What happens to electrons in covalent bonding?
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Pairs are shared between atoms
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Electrons transfer from one atom to another
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Outer electrons delocalise through a lattice
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Protons move between atomic nuclei
Question 4
Metallic bonding is the attraction between?
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Positive metal ions and delocalised electrons
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Negative ions and shared electron pairs
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Neutral atoms and neutrons
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Molecules and hydrogen ions
Question 5
Why do ionic compounds usually have high melting points?
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Strong attractions act throughout a giant lattice
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Weak attractions act throughout a giant lattice
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Strong attractions act between small molecules
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Mobile ions repel as the solid is heated
Question 6
Why do simple molecular substances often melt easily?
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Forces between molecules are weak
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Forces between molecules are strong
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Covalent bonds inside molecules are weak
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Mobile ions separate from a giant lattice
Question 7
Why can graphite conduct electricity?
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Delocalised electrons move along its layers
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Carbon ions move between its layers
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Carbon atoms move through its lattice
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Every electron is fixed in a covalent bond
Question 8
Why is diamond very hard?
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Strong bonds extend throughout a giant lattice
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Layers slide over one another easily
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Weak forces act between separate molecules
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Mobile ions move through its lattice
Question 9
Which substance has ionic bonding?
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Sodium chloride (NaCl)
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Oxygen (O2)
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Methane (CH4)
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Carbon dioxide (CO2)
Question 10
Which substance is a simple molecular covalent substance?
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Carbon dioxide (CO2)
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Sodium chloride (NaCl)
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Magnesium oxide (MgO)
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Silicon dioxide (SiO2)
Question 11
When does sodium chloride conduct electricity?
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Molten or dissolved in water
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Solid at room temperature
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Gaseous at room temperature
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Solid or dissolved in oil
Question 12
Why are metals malleable?
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Ion layers slide while metallic bonding remains
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Shifted ion layers align like charges and repel
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Small molecules move through weak forces
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Covalent bonds break between separate molecules
Question 13
What is a polymer?
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A very large molecule made from repeating smaller units
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A pure metal with delocalised electrons
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A compound made from ionic crystals
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A gas with a low boiling point
Question 14
Which statement about water (H2O) is correct?
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It is a covalent compound with shared electrons
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It is an ionic compound with transferred electrons
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It is a metallic structure of hydrogen and oxygen ions
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It is a mixture, not a compound
Question 15
Why are ionic solids brittle?
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Shifted layers align like charges, causing repulsion
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Shifted layers keep metallic bonding intact
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Weak forces let small molecules slide
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Delocalised electrons hold flexible layers together
Question 16
Which formula represents methane?
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CH4
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C2H6
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CO2
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H2O
Question 17
Which substance has a giant covalent structure?
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Silicon dioxide (SiO2)
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Oxygen (O2)
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Hydrogen chloride (HCl)
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Water (H2O)
Question 18
Why does solid copper conduct electricity?
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Delocalised electrons move through the lattice
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Positive ions move through the lattice
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Electrons jump between separate molecules
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Protons move between atomic nuclei
Question 19
Why do atoms share electrons in covalent bonding?
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To fill outer shells and become more stable
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To increase the number of protons
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To form positively charged ions
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To remove the outer-shell electrons
Question 20
Which pair of element types most often forms an ionic compound?
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A metal and a non-metal
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Two non-metals
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Two noble gases
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Two transition metals
Question 21
What is a molecule?
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Atoms joined by covalent bonds
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Ions held in a giant lattice
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Metal ions among delocalised electrons
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Elements mixed without chemical bonds
Question 22
What forms when an atom loses electrons?
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A positive ion
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A negative ion
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A neutral molecule
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A different element
Question 23
What forms when an atom gains electrons?
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A negative ion
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A positive ion
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A neutral molecule
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A different element
Question 24
What is an ion?
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A charged atom or group of atoms
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A neutral atom with equal charges
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A molecule sharing electron pairs
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A mixture of unbonded substances
Question 25
Why do ionic compounds conduct when molten?
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Their ions can move
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Electrons move between the ions
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The atoms become neutral
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Covalent bonds break in the lattice
Question 26
Which substance has simple molecules?
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Carbon dioxide
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Sodium chloride
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Diamond
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Copper
Question 27
Why do simple molecular substances usually not conduct electricity?
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They have no mobile charged particles
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Their ions are fixed in a giant lattice
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Their delocalised electrons move too slowly
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Their covalent bonds block moving ions
Question 28
Why can metals conduct electricity?
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Delocalised electrons move through the structure
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Positive metal ions move through the solid
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Shared electron pairs move between molecules
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Outer electrons remain fixed to each atom
Question 29
What is an alloy?
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A metal mixed with other elements
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A pure metal
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A compound of non-metals
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A solution of acid and water
Question 30
What holds oppositely charged ions together?
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Electrostatic attraction
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Shared electron pairs
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Delocalised electrons
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Intermolecular forces