Chemistry: Structure, Bonding, and Earth's Atmosphere

What are the three states of matter?

Solid, liquid, and gas.

How can you determine the state of a substance at a given temperature?

By using data related to the substance's melting and boiling points.

What does the particle model describe regarding heating and cooling substances?

It describes how energy, movement, and attraction between particles change.

What processes can you describe regarding states of matter?

Melting, freezing, boiling, and condensing.

What happens to particles at the melting point or boiling point of a substance?

The energy and temperature of the substance change, affecting particle movement and attraction.

What factors affect the rate of evaporation?

Temperature, surface area, and air movement.

What is the significance of the particle model in representing states of matter?

It helps visualize how particles are arranged in solids, liquids, and gases.

What particles are involved in ionic bonding?

Cations (positive ions) and anions (negative ions).

How can you represent ionic compounds using dot and cross diagrams?

By showing the transfer of electrons between atoms.

How does a Group 1 metal atom become a positive ion?

By losing one electron.

What is the charge of a monatomic ion based on its position in the periodic table?

It can be suggested based on the group number of the element.

How does electron transfer facilitate ionic bonding?

It occurs when a Group 1 metal reacts with a Group 7 non-metal, resulting in the formation of ions.

How does a Group 7 non-metal atom become a negative ion?

By gaining one or more electrons.

What is the relationship between opposite charges in ionic bonding?

Opposite charges attract each other.

How can you determine the charge on unfamiliar ions?

By using the position of the element in the periodic table.

What are the charges of ions in Group 1, Group 2, Group 6, and Group 7 elements?

Group 1: +1, Group 2: +2, Group 6: -2, Group 7: -1.

What is an ionic lattice?

A structured arrangement of ions in an ionic compound.

What are the properties of ionic compounds?

They have high melting points and can dissolve in water.

Why do ionic compounds have high melting points?

Due to the strong electrostatic forces between the ions in the lattice.

Why can ionic compounds conduct electricity when molten or in solution but not when solid?

In solid form, ions are fixed in place; when molten or dissolved, they can move freely.

How can an ionic compound conduct electricity?

Ionic compounds can conduct electricity when molten or dissolved in water due to the movement of ions.

What is a covalent bond?

A covalent bond is a chemical bond formed when two atoms share one or more pairs of electrons.

How does a covalent bond form in terms of electronic structure?

A covalent bond forms when atoms share electrons to achieve a full outer shell, stabilizing their electronic structure.

What are the characteristics of small molecules with covalent bonds?

Small molecules typically have low melting and boiling points and do not conduct electricity.

How do double and triple covalent bonds differ from single covalent bonds?

Double and triple covalent bonds involve the sharing of two or three pairs of electrons, respectively, leading to stronger bonds and different physical properties compared to single bonds.

What are intermolecular forces?

Intermolecular forces are the forces of attraction or repulsion between neighboring molecules.

What types of substances have weak intermolecular forces?

Substances with small, nonpolar molecules typically have weak intermolecular forces.

What are the main physical properties of diamond?

Diamond is hard, has a high melting point, and is an excellent electrical insulator.

What are the main physical properties of graphite?

Graphite is soft, has a high melting point, and can conduct electricity due to the movement of delocalized electrons.

How does the structure of graphite relate to its properties?

Graphite has layers of carbon atoms that can slide over each other, making it soft and lubricating, while delocalized electrons allow it to conduct electricity.

What is the significance of the high melting points of giant covalent structures?

Giant covalent structures have high melting points due to the strong covalent bonds that need to be broken to change the state.

How can the properties of a double bond differ from a single covalent bond?

Double bonds are generally stronger and shorter than single bonds, affecting the physical properties of the molecules.

What is the role of molecular models in predicting physical properties?

Molecular models help visualize and predict the physical properties of substances based on their bonding and structure.

What is a dot and cross diagram?

A dot and cross diagram is a representation of covalent bonding where dots represent one atom's electrons and crosses represent another's.

What is a ball and stick diagram?

A ball and stick diagram is a model that represents atoms as balls and bonds as sticks, illustrating the arrangement of atoms in a molecule.

How can you recognize a covalent compound from its formula?

Covalent compounds typically consist of nonmetals and can be identified by their molecular formulas, such as H2O or NH3.

What are the limitations of molecular models?

Molecular models can oversimplify complex structures and may not accurately represent the dynamics of molecular interactions.

How do you predict the physical properties of unfamiliar covalently bonded substances?

By analyzing the type of bonding, molecular size, and intermolecular forces, one can predict the physical properties of unfamiliar covalently bonded substances.

What is the significance of the electronic structure in bonding?

The electronic structure determines how atoms bond, influencing the type of bond (ionic or covalent) and the resulting properties of the compound.

What is the relationship between graphite and graphene?

Graphene is a single layer of carbon atoms arranged in a two-dimensional honeycomb lattice, while graphite is composed of multiple layers of graphene.

What are the structures of fullerenes and nanotubes?

Fullerenes are spherical or ellipsoidal molecules made entirely of carbon, while nanotubes are cylindrical structures made of graphene rolled into a tube.

What are some applications of fullerenes?

Fullerenes are used in drug delivery, as antioxidants, in solar cells, and in materials science for their unique properties.

What are the main physical properties of fullerenes?

Fullerenes exhibit unique properties such as high strength, electrical conductivity, and the ability to act as electron acceptors.

What is the molecular formula of buckminsterfullerene?

The molecular formula of buckminsterfullerene is C60.

What are the properties and uses of carbon nanotubes?

Carbon nanotubes have high tensile strength, electrical conductivity, and thermal conductivity, making them useful in electronics, materials reinforcement, and nanotechnology.

What type of structure do metals form?

Metals form a giant metallic structure.

What is metallic bonding?

Metallic bonding is the electrostatic attraction between positively charged metal ions and delocalized electrons.

How do metal atoms form giant structures?

Metal atoms lose their outer electrons, which become delocalized and create a sea of electrons that hold the metal ions together in a giant structure.

How can metallic bonding be represented diagrammatically?

Metallic bonding can be represented by diagrams showing a lattice of metal ions surrounded by a sea of delocalized electrons.

What are the physical properties of metals?

Metals are typically malleable, ductile, good conductors of heat and electricity, and have high melting and boiling points.

How does alloying affect the structure and bonding in metals?

Alloying introduces different atoms into the metallic structure, disrupting the regular arrangement of metal ions, which affects properties such as strength and ductility.

What is the structure of a pure metal?

A pure metal consists of closely packed metal ions arranged in a regular lattice structure.

Why are metals alloyed?

Metals are alloyed to enhance properties such as strength, corrosion resistance, and hardness.

Why are alloys more often used than pure metals?

Alloys are often more durable, stronger, and have better resistance to corrosion compared to pure metals.

What is nanoscience?

Nanoscience is the study of structures and materials on the nanoscale, typically between 1 and 100 nanometers.

How is the size of nanoparticles described?

Nanoparticles are typically defined as particles with sizes ranging from 1 to 100 nanometers.

How can particles be classified based on size?

Particles can be classified as coarse, fine, or nanoparticles based on their size.

How does surface area to volume ratio change as particle size decreases?

As particle size decreases, the surface area to volume ratio increases.

Why does the surface area to volume ratio increase with smaller particle size?

Smaller particles have a greater surface area relative to their volume, leading to increased reactivity and interaction with their environment.

What are the advantages and disadvantages of using nanoparticles?

Advantages include increased reactivity and enhanced properties, while disadvantages may include potential toxicity and environmental impact.

What are some uses of nanoparticles?

Nanoparticles are used in applications such as drug delivery, sun creams, electronics, and materials science.

Why should nanotechnology research continue?

Nanotechnology research should continue due to its potential for innovative applications and solutions in medicine, energy, and materials.

What is the atmosphere?

A protective layer of gases that surrounds Earth.

What are the main components of Earth's atmosphere?

Nitrogen (78%), oxygen (21%), argon (0.9%), carbon dioxide (0.04%), other noble gases, and water vapour.

How has the composition of the atmosphere remained over the last 200 million years?

The amounts of gases in the atmosphere have remained much the same.

How did carbon get 'locked away' in rocks and fossil fuels?

Shelled sea animals used CO2 to make calcium carbonate shells, which formed limestone. Algae and plankton photosynthesised in CO2-rich oceans, and their remains formed oil and natural gas. Photosynthesising plants absorbed CO2, and their remains formed coal.

How did the atmosphere form?

Earth's early atmosphere was formed by erupting volcanoes releasing carbon dioxide, water vapour, and nitrogen.

What has caused the increase in CO2 and methane levels in the atmosphere?

Human activities such as combustion of fossil fuels, intensive animal farming, and rubbish decomposition in landfills.

What effect does deforestation have on CO2 levels?

It leads to fewer trees, resulting in less CO2 being absorbed from the atmosphere for photosynthesis.

What happened to CO2 levels as the Earth cooled?

Water vapour condensed to form oceans, which dissolved CO2, reducing its amount in the atmosphere.

What significant evolutionary change occurred between 2.7 and 1.7 billion years ago?

Algae and plants evolved, using CO2 for photosynthesis and releasing oxygen, which increased O2 levels in the atmosphere.

What is global dimming and what causes it?

Global dimming is the reduction of sunlight reaching Earth, caused by particulates from incomplete combustion of hydrogen fuels.

What is carbon monoxide and why is it dangerous?

Carbon monoxide (CO) is a poisonous gas produced by incomplete combustion.

What is sulfur dioxide and how is it produced?

Sulfur dioxide (SO2) is produced by burning fossil fuels that contain sulfur, which reacts with oxygen in the air.

What is the significance of the atmosphere being compared to the thickness of an apple's skin?

It illustrates that the atmosphere is very thin relative to the size of the Earth.

What role did photosynthesising plants play in the development of the atmosphere?

They absorbed CO2 and released oxygen, contributing to the increase of O2 levels.

What is the percentage of oxygen in Earth's atmosphere?

21%.

What is the percentage of nitrogen in Earth's atmosphere?

78%.

What is the percentage of argon in Earth's atmosphere?

0.9%.

What is the percentage of carbon dioxide in Earth's atmosphere?

0.04%.

What are noble gases and where are they found in the atmosphere?

Noble gases are a small percentage of gases in the atmosphere, alongside nitrogen, oxygen, argon, and carbon dioxide.

What is the effect of human activity on pollutant levels in the atmosphere?

Pollutant levels have increased due to various human activities.

How can this knowledge organiser be used effectively?

It can be used for reference, catch-up, recapping, or revising for tests and exams.

What is the role of algae and plankton in the carbon cycle?

They photosynthesised in CO2-rich oceans, contributing to the formation of fossil fuels.

How did the early atmosphere contribute to the development of life?

The early atmosphere provided the necessary gases for photosynthesis, leading to the evolution of oxygen-producing organisms.

What is the greenhouse effect?

A natural process that warms the Earth's surface, keeping the average temperature around 16°C.

What would the average temperature on Earth be without the greenhouse effect?

Around -18°C, the temperature of a freezer.

What gases are considered greenhouse gases?

Carbon dioxide (CO2), methane (CH4), and water vapour (H2O).

How can we reduce methane (CH4) levels?

By eating more plant-based foods.

What are some activities to reduce carbon dioxide (CO2) levels?

Using renewable energy supplies (e.g., wind, solar), carbon-offsetting by planting trees, and improving energy efficiency.

What is a carbon footprint?

The amount of carbon dioxide and other greenhouse gases released over the full life cycle of a product.

What is the goal of governments and businesses regarding greenhouse gases?

To achieve net zero, balancing the amount produced with the amount removed from the atmosphere.

What happens to short wave solar radiation from the Sun?

It passes through the Earth's atmosphere and is absorbed by the Earth's surface, warming it.

What occurs to some of the heat energy after it warms the Earth?

Some heat energy radiates back towards Earth, while some is lost in space.

What is the impact of increased carbon dioxide and methane in the atmosphere?

It has caused the average temperature of the Earth to increase, leading to global warming.

What are some effects of global warming?

Increasing temperatures, melting polar ice caps, rising sea levels, changes in rainfall, and more frequent severe storms.

How does the greenhouse effect contribute to warming the Earth?

It traps heat energy radiated back from the Earth, preventing it from escaping into space.

What are the consequences of changing rainfall patterns due to global warming?

Water shortages and drought, which affect food production.

What changes can occur in wildlife due to global warming?

Changes in distribution of species, migration patterns, and biodiversity.

What is one method of carbon capture?

Trapping CO2 produced by power stations.