Practice Questions for Year 11 Chemistry Module 1: Properties and Structure of Matter

Atomic Structure and Atomic Mass

Inquiry Question: Why are atoms of elements different from one another?  

Question 6 ⭐

With reference to the molecular structure of elements, explain the trends in reactivity of the elements as you. (4 marks) 

a) Move across the periodic table 

b) Move down the periodic table

(L2.1: investigate the basic structure of stable and unstable isotopes by examining their position in the periodic table, the distribution of electrons, protons and neutrons in the atom and representation of the symbol, atomic number and mass number (nucleon number))

Question 7 ⭐⭐

Explain how the composition of electrons, protons and neutrons in the atom contribute to the stability of the isotope. (3 marks) 

(L2.1: investigate the basic structure of stable and unstable isotopes by examining their position in the periodic table, the distribution of electrons, protons and neutrons in the atom and representation of the symbol, atomic number and mass number (nucleon number))

Question 8 ⭐⭐⭐

Determine the neutron to proton ratio (N:Z) of the following atoms and thus, its stability. (8 marks)

a) Ru-99

b) Pt-190

c) Ca-48

d) Kr-86

(L2.1: investigate the basic structure of stable and unstable isotopes by examining their position in the periodic table, the distribution of electrons, protons and neutrons in the atom and representation of the symbol, atomic number and mass number (nucleon number))

Question 9 ⭐⭐

Write the electronic configuration and the spdf notation for the following elements. (16 marks)

a) Lithium 

b) Sodium 

c) Sulfur 

d) Oxygen

e) Carbon

f) Zinc

g) Iron

h) Neon 

(L2.2: model the atom’s discrete energy levels, including electronic configuration and spdf notation)

If these Module 1 Chemistry questions have you feeling overwhelmed, our award-winning Chemistry tutors near you can support you with tailored one on one tutoring in the comfort of your home or online.

Question 10 ⭐⭐

Using the diagram below:

a) Determine the relative abundance of the two chlorine isotopes as percentages. (2 marks)

b) Determine the atomic weight of chlorine using the mass spectrum data. (2 marks)

Image sourced from Web Elements

(L2.3: calculate the relative atomic mass from isotopic composition)

Question 11 ⭐

Illustrate why the shape of a water molecule is bent and not linear. Include diagrams. (3 marks)

(L4.2: investigate the differences between ionic and covalent compounds through modelling the shapes of molecular substances)

Question 12 ⭐⭐⭐🔥

Assess the advantages and limitations of the Bohr model and the Schrödinger model as an account for spectral analysis. (6 marks) 

(L2.4: investigate energy levels in atoms and ions through examining spectral evidence for the Bohr model and introducing the Schrödinger model)

Question 13 ⭐⭐⭐

A scientist has found a new element, X and has derived the following to describe the new element: 

Predict whether this new element is stable or unstable. Provide explanations (3 marks).

(L2.5: investigate the properties of unstable isotopes using natural and human-made radioisotopes as examples, including but not limited to types of radiation and types of balanced nuclear reactions)

Question 14 ⭐⭐⭐

Write the nuclear decay equation that results in the following isotopes with their respective decay. (5 marks)

a) Th-234 (alpha decay)

b) U-234 (beta decay)

c) Ra-226 (alpha decay) 

d) Xe-131 (beta decay) 

(L2.5: investigate the properties of unstable isotopes using natural and human-made radioisotopes as examples, including but not limited to types of radiation and types of balanced nuclear reactions)

Periodicity

Inquiry Question: Are there patterns in properties of elements? 

Question 15 ⭐⭐⭐

Carbon has many allotropes. Discuss how the structure of 3 carbon allotropes contribute to their uses. (7 marks) 

(L4.3: investigate elements that possess the physical property of allotropy)

Question 16 ⭐⭐⭐

A scientist has found an element with a large atomic radii.

What implications does this have on its electronic configuration, reactivity with water and most probable state of matter at room temperature? Provide explanations. (6 marks) 

(L3.1: demonstrate, explain and predict the relationships in the observable trends in the physical and chemical properties of elements in periods and groups in the periodic table, including but not limited to the state of matter at room temperature, electronic configurations and atomic radii, first ionisation energy and electronegativity and reactivity with water)

Question 17 ⭐⭐

Explain why the second ionization energy is lower than the first ionization energy with reference to the structure and composition of the element. (3 marks) 

(L3.1: demonstrate, explain and predict the relationships in the observable trends in the physical and chemical properties of elements in periods and groups in the periodic table, including but not limited to the state of matter at room temperature, electronic configurations and atomic radii, first ionisation energy and electronegativity and reactivity with water)

Bonding

What binds atoms together in elements and compounds? 

Question 18 ⭐⭐⭐🔥

Using their electronegativities, determine whether the following elements will form an ionic or covalent bond. Include calculations. (10 marks) 

a) Sodium and fluoride 

b) Magnesium and oxygen 

c) Lead and chloride 

d) Potassium and sulfur 

e) Beryllium and Selenium 

(L4.1: investigate the role of electronegativity in determining the ionic or covalent nature of bonds between atoms)

Question 19 ⭐⭐

Using Lewis dot diagrams, explain the differences between the ionic bond between NaCl and the covalent bond of H2O. (4 marks) 

(L4.2: investigate the differences between ionic and covalent compounds through using nomenclature, valency and chemical formulae (including Lewis dot diagrams)

Question 20 ⭐

Explain how intramolecular and intermolecular bonds differ, with reference to its effect on the strength of a named compound (4 marks). 

Question 1

Question 2

Step 1: Filter to remove sand.

Step 2: Evaporate the ethanol (as it has a lower boiling point than water).

Step 3: Evaporate water, allowing salt to recrystallize.

Question 3

Question 4

💡TIP: Don’t forget to write transition states for oxidation metals!

1. Ammonium chloride
2. Magnesium carbonate
3. Mercury(II) nitrate
4. Chromium(III) fluoride
5. Cobalt(II) Hydrogen sulfate
6. Rubidium Nitrate
7. Titanium(II) hydroxide
8. iron(II) hydrogen phosphate

Question 5

Question 6

a) As you move across the periodic table, the size of atomic radii decreases, and the ionization energy and electronegativity increases. The atomic radii decreases as there is a greater attraction between particles, resulting in a tighter control over particles. This means more energy is required to remove an electron, and a higher “need” for the element to complete its outer shell.

b) Moving down the periodic table results in an increase in size of the atomic radii, and a decrease in ionization energy and electronegativity. The larger an atomic radii becomes, the harder it is for it to hold on to all its particles (decrease in attraction). This results in less energy being required to remove an electron and a lower demand on completing the outer shell.

Question 7

When it comes to the stability of an isotope, all components of the atom will contribute. Stability of an isotope is generally determined using the N:Z ratio, which indicates the balance of protons and neutrons within the atom. If the N:Z ratio is close to one, there are an almost equal amount of neutrons to protons resulting in a stable isotope. However if the N:Z ratio is decently below or above one, there are too many neutrons or protons present, resulting in an unstable isotope. Lastly, electrons have a minimal effect on stability, but still balance the overall charge of the atom.

Question 8

💡TIP: Remember that for elements to be stable, the N:Z ratio has to be close to 1.

As the proton ratio (N:Z) is the only factor taken into consideration when determining the stability, all are stable. However, the further away from one the N:Z ratio becomes, the more the atoms incline to instability.

Question 9

Question 10

Question 11

The repulsion between the lone pairs and bonding pairs of electrons results in “uneven” gaps. Furthermore, oxygen is more electronegative, meaning it doesn’t want to break its existing electron pairs. This results in the established pairs having a partial negative charge as seen below.

Question 12

The Bohr model is simpler and compares atoms to mini solar systems, stating that electrons revolve around the nucleus in fixed circular orbits (shells). For electrons to transition between energy levels, they absorb or emit photons. The Bohr model explains line spectra for hydrogen and can predict spectral  lines for single-electron systems, however it cannot explain multi-electron atom spectra and views electrons only as particles in fixed orbits.

The Schroedinger model is more complex and defines electrons as wave functions. This definition of electrons allows for accurate interpretation of spectra for multi-electron atoms, and includes a more detailed understanding of electron behaviour through shell sublevels (spdf orbitals). The Schroedinger model can more precisely match observed emission spectra compared to the Bohr model.

Question 13

Question 14

💡TIP: Alpha decay involves a Helium atom (or alpha particle), and beta decay involves an electron (or beta particle).

Question 15

💡TIP: For diamond and graphite, think of things like diamond pickaxes in minecraft and your school pencils!

Three of carbons allotropes are diamond, graphite and buckminsterfullerene.
Diamond is formed out of a rigid, tetrahedral carbon lattice, making it the hardest natural material. Graphite is a soft and slippery material made out of hexagonal carbon ring stacks. Buckminsterfullerene structurally looks like a soccer ball and is made out of 60 carbons.

The structural differences between these carbon allotropes allow for different uses. Diamond being incredibly rigid and strong is great for cutting other materials. Graphite is easily transferred through pressure due to its soft and slippery nature, which is why it’s used in pencils. Buckminsterfullerene is used in electronics and medicine due to its high surface to volume ratio. 

Question 16

💡TIP: Where on the periodic table can we find elements with large atomic radii, and what do we know about them

A large atomic radii will have the following implications. Due to its large size, the electronic configuration will have a large principal quantum number (n) with a weaker attraction. Elements with large atomic radii are generally metals and are incredibly reactive in water as they lose electrons easily. As they are most likely metals, they will be in a solid state at room temperature. However, depending on the bonding or structure of the element it is possible that it is gaseous or liquid.

Question 17

The second ionization energy is always higher than the first. This is because removing an electron from an already positively charged ion requires more energy than removing an electron from a neutral element.

Question 18

1. Sodium and fluoride will form an ionic bond as their change in electronegativity is greater than 1.7, and the compound consists of one metal and one non-metal element.
   3.98-0.93=3.05
2. Magnesium and oxygen also form ionic bonds as they consist of one metal and one non-metal and their difference in electronegativity is greater than 1.7
   3.44-1.31=2.13
3. Even though lead is a metal and chloride is a non-metal, the change in electronegativity is less than 1.7, indicating they will form a covalent bond
   3.16-2.33=0.83
4. Potassium and sulfur are a metal and non-metal pairing with a difference in electronegativity (just) greater than 1.7 resulting in an ionic bond.
   2.58-0.82=1.76
5. Beryllium and selenium, whilst consisting of a metal and non-metal combination still have a change in electronegativity lower than 1.7 creating a covalent bond.
   2.55-1.57=0.98

Question 19

The ionic bond between NaCl is created through an electron transfer due to high electrostatic attraction as seen in the diagram below.

However the covalent bond of H₂O is illustrated below through the sharing of electrons.

Covalent bonds result in separate molecules, whilst ionic bonds often form lattice structures.

Question 20

Intramolecular forces are the forces within a molecule. They are strong chemical bonds between atoms that can be covalent or ionic. In contrast, intermolecular forces exist between molecules. They are weaker than intramolecular forces and represent the attraction between different molecules. These are classified as dispersion forces, dipole-dipole forces, or hydrogen bonding. Water (H₂O) has strong and stable covalent bonds (intramolecular) and hydrogen bonds between molecules (intermolecular).