Question 1

The energy levels of electrons in their orbitals are determined by

Accepted Answer

A)  the distance of the orbital from the nucleus. 
B)  the number of electrons in the orbital. 
C)  the number of neutrons in the nucleus. 
D)  the number of protons in the orbital. 
E)  the distance of the electrons in the orbital from each other. 
A)  the distance of the orbital from the nucleus. 
B)  the number of electrons in the orbital. 
C)  the number of neutrons in the nucleus. 
D)  the number of protons in the orbital. 
E)  the distance of the electrons in the orbital from each other. A

Question 2

When two atoms share a pair of electrons, the type of bonding is termed

Accepted Answer

A)  ionic. 
B)  hydrogen. 
C)  covalent. 
D)  non-covalent. 
E)  unstable. 
A)  ionic. 
B)  hydrogen. 
C)  covalent. 
D)  non-covalent. 
E)  unstable. C

Question 3

An oxygen atom has 8 protons, 8 neutrons and 8 electrons.

Accepted Answer

A)  Its atomic number is 16. 
B)  Its mass number is 8. 
C)  It has 4 electrons in the first energy level (electron shell). 
D)  It has 6 electrons in the outermost energy level (electron shell). 
E)  It has 8 electrons in the outermost energy level (electron shell). 
A)  Its atomic number is 16. 
B)  Its mass number is 8. 
C)  It has 4 electrons in the first energy level (electron shell). 
D)  It has 6 electrons in the outermost energy level (electron shell). 
E)  It has 8 electrons in the outermost energy level (electron shell). D

Question 4

Which of the following atoms is NOT among those most commonly found to bind to carbon?

Accepted Answer

A)  Oxygen. 
B)  Hydrogen. 
C)  Sulfur. 
D)  Potassium. 
E)  Nitrogen. 
A)  Oxygen. 
B)  Hydrogen. 
C)  Sulfur. 
D)  Potassium. 
E)  Nitrogen.

Question 5

Carbon has 4 electrons in its outer shell available for covalent bonding. Which of the following statements about carbon is INCORRECT?

Accepted Answer

A)  Carbon is able to share the electrons with 4 atoms of hydrogen. 
B)  Carbon is able to share the electrons with other carbon atoms to form biomolecules. 
C)  Carbon is able to share electrons with oxygen to form carbon dioxide. 
D)  Carbon is able to form stable molecules by gaining 4 electrons in its outer electron orbital. 
E)  Carbon is able to form highly reactive molecules by losing 2 of the 4 electrons in its outer electron orbital. 
A)  Carbon is able to share the electrons with 4 atoms of hydrogen. 
B)  Carbon is able to share the electrons with other carbon atoms to form biomolecules. 
C)  Carbon is able to share electrons with oxygen to form carbon dioxide. 
D)  Carbon is able to form stable molecules by gaining 4 electrons in its outer electron orbital. 
E)  Carbon is able to form highly reactive molecules by losing 2 of the 4 electrons in its outer electron orbital.

Question 6

The mass number of an atom is the number of

Accepted Answer

A)  protons in the nucleus of an atom. 
B)  protons and neutrons combined in the nucleus of an atom. 
C)  neutrons in the nucleus of an atom. 
D)  electrons in an atom. 
E)  protons and electrons combined in an atom. 
A)  protons in the nucleus of an atom. 
B)  protons and neutrons combined in the nucleus of an atom. 
C)  neutrons in the nucleus of an atom. 
D)  electrons in an atom. 
E)  protons and electrons combined in an atom.

Question 7

When atoms gain or lose electrons from their orbital and so become charged, they are called

Accepted Answer

A)  unstable. 
B)  non-covalent. 
C)  isotopes. 
D)  radioactive. 
E)  ions. 
A)  unstable. 
B)  non-covalent. 
C)  isotopes. 
D)  radioactive. 
E)  ions.

Question 8

Which of the following statements is INCORRECT?

Accepted Answer

A)  A buffer solution maintains a relatively constant pH either by removing hydrogen ions or by releasing them. 
B)  Water molecules ionise and dissociate forming both hydrogen (H+) and hydroxyl ions (OH-). 
C)  The pH is the concentration of hydrogen ions in the solution. 
D)  The pH is the concentration of hydroxyl ions in the solution. 
E)  The pH scale is logarithmic. 
A)  A buffer solution maintains a relatively constant pH either by removing hydrogen ions or by releasing them. 
B)  Water molecules ionise and dissociate forming both hydrogen (H+) and hydroxyl ions (OH-). 
C)  The pH is the concentration of hydrogen ions in the solution. 
D)  The pH is the concentration of hydroxyl ions in the solution. 
E)  The pH scale is logarithmic.

Question 9

In regard to chemical bonding, what is the order of bond strength from weakest to strongest?

Accepted Answer

A)  Van der Waals, Hydrogen, Ionic, Covalent 
B)  Covalent, Ionic, Hydrogen, van der Waals 
C)  Hydrogen, Covalent, Ionic, van der Waals 
D)  Van der Waals, Ionic, Hydrogen, Covalent 
E)  Ionic, Hydrogen, van der Waals, Covalent 
A)  Van der Waals, Hydrogen, Ionic, Covalent 
B)  Covalent, Ionic, Hydrogen, van der Waals 
C)  Hydrogen, Covalent, Ionic, van der Waals 
D)  Van der Waals, Ionic, Hydrogen, Covalent 
E)  Ionic, Hydrogen, van der Waals, Covalent

Question 10

Nitrogen has 5 electrons in its outer orbital which allows it to share its electrons with

Accepted Answer

A)  2 hydrogen atoms. 
B)  3 hydrogen atoms. 
C)  4 hydrogen atoms. 
D)  5 hydrogen atoms. 
E)  6 hydrogen atoms. 
A)  2 hydrogen atoms. 
B)  3 hydrogen atoms. 
C)  4 hydrogen atoms. 
D)  5 hydrogen atoms. 
E)  6 hydrogen atoms.

Question 11

One of the properties that make water an ideal medium for living organisms is that water

Accepted Answer

A)  can absorb considerable amounts of heat with little change in temperature. 
B)  expands and becomes more dense as it changes from solid to liquid form. 
C)  releases heat when it evaporates. 
D)  is a universal solvent. 
E)  has a high boiling point. 
A)  can absorb considerable amounts of heat with little change in temperature. 
B)  expands and becomes more dense as it changes from solid to liquid form. 
C)  releases heat when it evaporates. 
D)  is a universal solvent. 
E)  has a high boiling point.

Question 12

Like carbon, silicon can form complex molecules yet silicon-based life has not been found. Why not?

Accepted Answer

A)  Carbon preferentially displaces silicon in extensive polymers. 
B)  Silicon atoms are not present in the lithosphere at high enough concentrations. 
C)  The covalent bonds between silicon atoms yield less energy when oxidised. 
D)  The oxide of silicon is a liquid. 
E)  Silicon is not a tetravalent atom. 
A)  Carbon preferentially displaces silicon in extensive polymers. 
B)  Silicon atoms are not present in the lithosphere at high enough concentrations. 
C)  The covalent bonds between silicon atoms yield less energy when oxidised. 
D)  The oxide of silicon is a liquid. 
E)  Silicon is not a tetravalent atom.

Question 13

Elements in living organisms are

Accepted Answer

A)  similar to those found generally in the biosphere. 
B)  not similar to those found in the biosphere. 
C)  mainly carbon (
C)  and sodium chloride (NaCl). 
D)  highly reactive. 
E)  mostly atoms with a high atomic mass. 
A)  similar to those found generally in the biosphere. 
B)  not similar to those found in the biosphere. 
C)  mainly carbon (
C)  and sodium chloride (NaCl). 
D)  highly reactive. 
E)  mostly atoms with a high atomic mass.

Question 14

Ionic bonds are formed by the

Accepted Answer

A)  attraction between atoms with opposite polarity. 
B)  transfer of electrons from one atom to another. 
C)  sharing of electrons between oppositely charged ions. 
D)  attraction between positively and negatively charged ions of the same element. 
E)  sharing of electrons in the outer electron orbital of an atom. 
A)  attraction between atoms with opposite polarity. 
B)  transfer of electrons from one atom to another. 
C)  sharing of electrons between oppositely charged ions. 
D)  attraction between positively and negatively charged ions of the same element. 
E)  sharing of electrons in the outer electron orbital of an atom.

Question 15

Water is a versatile solvent because water molecules are

Accepted Answer

A)  small. 
B)  polar. 
C)  hydrophilic. 
D)  loosely connected by hydrogen bonds. 
E)  hydrophobic. 
A)  small. 
B)  polar. 
C)  hydrophilic. 
D)  loosely connected by hydrogen bonds. 
E)  hydrophobic.

Question 16

Hydrogen bonding between water molecules gives water a high level of structural organisation. In ice, the maximum number of hydrogen bonds formed with one water molecule is

Accepted Answer

A)  2. 
B)  3. 
C)  4. 
D)  6. 
E)  1. 
A)  2. 
B)  3. 
C)  4. 
D)  6. 
E)  1.

Question 17

Atoms of the same element can exist in different forms called isotopes. The most common isotope of carbon is carbon-12 but it has two less-common isotopes, carbon-13 and carbon-14. The less-common isotopes have

Accepted Answer

A)  the same number of electrons but more protons. 
B)  the same number of protons but more neutrons. 
C)  the same number of neutrons but more protons. 
D)  the same number of protons but more electrons. 
E)  the same number of neutrons but more electrons. 
A)  the same number of electrons but more protons. 
B)  the same number of protons but more neutrons. 
C)  the same number of neutrons but more protons. 
D)  the same number of protons but more electrons. 
E)  the same number of neutrons but more electrons.

Question 18

Compared with a pH of 7, a solution with a pH of 9 has

Accepted Answer

A)  2 times higher [H+] concentration. 
B)  2 times lower [H+] concentration. 
C)  1/100 the [H+] concentration. 
D)  100 times the [H+] concentration. 
E)  20 times lower [H+] concentration. 
A)  2 times higher [H+] concentration. 
B)  2 times lower [H+] concentration. 
C)  1/100 the [H+] concentration. 
D)  100 times the [H+] concentration. 
E)  20 times lower [H+] concentration.

Question 19

Buffers are substances that assist cells and organisms to resist changes in pH by

Accepted Answer

A)  accepting H+ ions as pH rises and releasing H+ ions as pH falls. 
B)  accepting OH- ions as pH rises and releasing H+ ions as pH falls. 
C)  accepting H+ ions as pH falls and releasing H+ ions as pH rises. 
D)  accepting OH- ions as pH falls and releasing H+ ions as pH rises. 
E)  accepting OH- ions as pH falls and releasing OH- ions as pH rises. 
A)  accepting H+ ions as pH rises and releasing H+ ions as pH falls. 
B)  accepting OH- ions as pH rises and releasing H+ ions as pH falls. 
C)  accepting H+ ions as pH falls and releasing H+ ions as pH rises. 
D)  accepting OH- ions as pH falls and releasing H+ ions as pH rises. 
E)  accepting OH- ions as pH falls and releasing OH- ions as pH rises.

Question 20

Which of the following statements about chemical bonds is CORRECT?

Accepted Answer

A)  Van der Waals forces allow temporary associations between molecules but the bonds are 100 times weaker than covalent bonds. 
B)  Covalent bonds involve the attraction between two ions of opposite charge. 
C)  Hydrogen bonds formed between hydrogen and oxygen atoms are strong, stable bonds. 
D)  In a molecule of water, the electrons are shared equally between the hydrogen and the oxygen molecule. This is the reason for the stability of water. 
E)  Ionic compounds result from the attraction between anions (positively charged ions) and cations (negatively charged ions). 
A)  Van der Waals forces allow temporary associations between molecules but the bonds are 100 times weaker than covalent bonds. 
B)  Covalent bonds involve the attraction between two ions of opposite charge. 
C)  Hydrogen bonds formed between hydrogen and oxygen atoms are strong, stable bonds. 
D)  In a molecule of water, the electrons are shared equally between the hydrogen and the oxygen molecule. This is the reason for the stability of water. 
E)  Ionic compounds result from the attraction between anions (positively charged ions) and cations (negatively charged ions).

Exam 1: Nature of Molecules

The energy levels of electrons in their orbitals are determined by

When two atoms share a pair of electrons, the type of bonding is termed

An oxygen atom has 8 protons, 8 neutrons and 8 electrons.

Which of the following atoms is NOT among those most commonly found to bind to carbon?

Carbon has 4 electrons in its outer shell available for covalent bonding. Which of the following statements about carbon is INCORRECT?

The mass number of an atom is the number of

When atoms gain or lose electrons from their orbital and so become charged, they are called

Which of the following statements is INCORRECT?

In regard to chemical bonding, what is the order of bond strength from weakest to strongest?

Nitrogen has 5 electrons in its outer orbital which allows it to share its electrons with

One of the properties that make water an ideal medium for living organisms is that water

Like carbon, silicon can form complex molecules yet silicon-based life has not been found. Why not?

Elements in living organisms are

Ionic bonds are formed by the

Water is a versatile solvent because water molecules are

Hydrogen bonding between water molecules gives water a high level of structural organisation. In ice, the maximum number of hydrogen bonds formed with one water molecule is

Atoms of the same element can exist in different forms called isotopes. The most common isotope of carbon is carbon-12 but it has two less-common isotopes, carbon-13 and carbon-14. The less-common isotopes have

Compared with a pH of 7, a solution with a pH of 9 has

Buffers are substances that assist cells and organisms to resist changes in pH by

Which of the following statements about chemical bonds is CORRECT?

Biomolecules

The Chemistry of Life

Functioning Cells

Movement Across Membranes

Harvesting Energy

Cells, Tissues and Signals

Cell Division

Inheritance

Genes, Chromosomes and Dna

The Genetic Code

Gene Expression

Genomes, Mutation and Cancer

Viruses

Genetic Engineering and Biotechnology

Reproduction, Growth and Development of Flowering Plants

Structure of Plants

Plant Nutrition, Transport and Adaptation to Stress

Plant Hormones and Growth Responses

Animal Reproduction

Animal Development

Homeostasis: Water, Solutes and Excretion

Gas Exchange in Animals

Circulation

Metabolism, Temperature Regulation and Environmental Stress

Animal and Human Nutrition

Innate Defences and the Immune System

Hormonal Control in Animals

Nervous Systems

Animal Movement

Animal Behaviour

Evolving Life

Evolving Earth

Mechanisms of Evolution

Bacteria

The Protists

Plants

Fungi

Simple Animals: Sponges to Flatworms

Annelids, Molluscs, Nematodes and Arthropods

Echinoderms and Chordates

Australian Biota

Population Ecology

Living in Communities

Ecosystems

Human Impacts

Filters