Bonding, Structure and Properties of Matter Flashcards
What are ions?
Ions are charged particles that can be single atoms or groups of atoms.
How are ions formed?
Ions are formed when atoms lose or gain electrons to achieve a full outer shell.
Which groups of elements are most likely to form ions?
Groups 1, 2, 6, and 7 are the most likely to form ions.
What happens when metals form ions?
When metals form ions, they lose electrons from their outer shell to form positive ions (cations).
What happens when non-metals form ions?
When non-metals form ions, they gain electrons into their outer shell to form negative ions (anions).
How is the charge of an ion determined?
The number of electrons lost or gained is the same as the charge on the ion. E.g., if 2 electrons are lost, the charge is 2+.
What do elements in the same group have in common?
Elements in the same group have the same number of outer electrons and form ions with the same charges.
What charge do Group I elements form?
Group I elements form 1+ ions.
What charge do Group 2 elements form?
Group 2 elements form 2+ ions.
What charge do Group 6 elements form?
Group 6 elements form 2- ions.
What charge do Group 7 elements form?
Group 7 elements form 1- ions.
How does a sodium atom (Na) form an ion?
A sodium atom loses 1 electron to form a sodium ion (Na+) with the same electronic structure as neon: Na → Na+ + e.
How does a magnesium atom (Mg) form an ion?
A magnesium atom loses 2 electrons to form a magnesium ion (Mg2+) with the same electronic structure as neon: Mg → Mg2+ + 2e.
How does a chlorine atom (Cl) form an ion?
A chlorine atom gains 1 electron to form a chloride ion (Cl-) with the same electronic structure as argon: Cl + e → Cl-.
How does an oxygen atom (O) form an ion?
An oxygen atom gains 2 electrons to form an oxide ion (O2-) with the same electronic structure as neon: O + 2e → O2-.
What are the three types of bonding?
Ionic, covalent, and metallic.
What happens during ionic bonding?
A metal atom loses electrons to form a positively charged ion, and a non-metal gains these electrons to form a negatively charged ion.
What is the attraction between oppositely charged ions called?
Ionic bond.
What do dot and cross diagrams represent?
The arrangement of electrons in an atom or ion, where each electron is represented by a dot or a cross.
How is sodium chloride (NaCl) formed?
The sodium atom gives up its outer electron, becoming an Na ion, while the chlorine atom picks up the electron, becoming a Cl ion.
What do the dots and crosses represent in sodium chloride’s dot and cross diagram?
Dots represent Na electrons and crosses represent Cl electrons.
How is magnesium oxide (MgO) formed?
The magnesium atom gives up its two outer electrons, becoming an Mg2+ ion, and the oxygen atom picks up the electrons, becoming an O2- ion.
How is magnesium chloride (MgCl2) formed?
The magnesium atom gives up its two outer electrons, becoming an Mg2+ ion, and two chlorine atoms pick up one electron each, becoming two Cl ions.
How is sodium oxide (Na2O) formed?
Two sodium atoms each give up their single outer electron, becoming two Na ions, while the oxygen atom picks up the two electrons, becoming an O2- ion.
What do dot and cross diagrams not show?
The structure of the compound, the size of the ions, or how they are arranged.
What is the significance of an atom’s group number in ionic bonding?
It helps determine how many electrons an atom will gain or lose.
What structure do ionic compounds have?
Ionic compounds have a structure called a giant ionic lattice.
How are ions arranged in an ionic compound?
The ions form a closely packed regular lattice arrangement.
What holds the ions together in an ionic lattice?
There are very strong electrostatic forces of attraction between oppositely charged ions.
What is a single crystal of sodium chloride?
A single crystal of sodium chloride is one giant ionic lattice.
What happens to ionic compounds when they melt?
When ionic compounds melt, the ions are free to move and can carry electric charge.
What are the properties of ionic compounds?
Ionic compounds have high melting points and high boiling points due to strong bonds between the ions.
What is required to overcome the attraction in ionic compounds?
It takes lots of energy to overcome the attraction between the ions.
What happens to ionic compounds when they dissolve in water?
The ions separate and are free to move in the solution, allowing them to carry electric charge.
How can you determine the empirical formula of an ionic compound?
You can work out the empirical formula from a diagram of the compound by balancing the charges of the ions.
What is the empirical formula for potassium and oxide ions?
The empirical formula is K2O.
What is ionic bonding?
The electrostatic attraction between oppositely charged ions is ionic bonding.
Why can ionic compounds conduct electricity when molten?
The ions are free to move when molten, allowing them to carry electric charge.
What are covalent bonds?
Covalent bonds are formed when non-metal atoms share pairs of electrons.
How do covalent bonds form?
The positively charged nuclei of the bonded atoms are attracted to the shared pair of electrons by electrostatic forces.
What do atoms share in covalent bonding?
Atoms only share electrons in their outer shells (highest energy levels).
What does each single covalent bond provide?
Each single covalent bond provides one extra shared electron for each atom.
Why do atoms make enough covalent bonds?
Each atom involved generally makes enough covalent bonds to fill up its outer shell, achieving the electronic structure of a noble gas.
In which compounds does covalent bonding occur?
Covalent bonding happens in compounds of non-metals (e.g., H2O) and in non-metal elements (e.g., Cl2).
What are dot and cross diagrams used for?
Dot and cross diagrams are used to show the bonding in covalent compounds.
What do the electrons in dot and cross diagrams represent?
Electrons drawn in the overlap between the outer orbitals of two atoms are shared between those atoms.
What do dot and cross diagrams not show?
They don’t show the relative sizes of the atoms, or how the atoms are arranged in space.
What does the displayed formula of ammonia (NH3) show?
The displayed formula shows the covalent bonds as single lines between atoms.
What is the molecular formula of ethane based on its diagram?
The molecular formula of ethane is C2H6.
What do 3D models of molecules show?
3D models show the atoms, the covalent bonds, and their arrangement in space.
What is a molecular formula?
A molecular formula shows how many atoms of each element are in a molecule.
How can you find the molecular formula of a simple molecular compound?
By counting up how many atoms of each element there are in any of the diagrams.
What is the significance of dot and cross diagrams?
They are a great way of showing how atoms are connected in large molecules.
What are allotropes of carbon?
Allotropes are different structural forms of the same element in the same physical state.
What is the structure of diamond?
Diamond has a giant covalent structure, made up of carbon atoms that each form four covalent bonds.
Why is diamond very hard?
The strong covalent bonds in diamond take a lot of energy to break, giving it a very high melting point.
Does diamond conduct electricity?
No, diamond doesn’t conduct electricity because it has no free electrons or ions.
What is the structure of graphite?
In graphite, each carbon atom forms three covalent bonds, creating sheets of carbon atoms arranged in hexagons.
Why does graphite have a high melting point?
Graphite has a high melting point due to the strong covalent bonds within the layers.
How does graphite conduct electricity?
Graphite conducts electricity because each carbon atom has one delocalised (free) electron that can move.
What are the properties of graphite?
Graphite is soft and slippery, making it ideal as a lubricating material.
What is graphene?
Graphene is a sheet of carbon atoms joined together in hexagons, just one atom thick.
What are the properties of graphene?
Graphene is very strong, incredibly light, and can improve the strength of composite materials without adding much weight.
What are fullerenes?
Fullerenes are molecules of carbon that can conduct electricity through the whole structure.
What shapes can fullerenes form?
Fullerenes can form spheres and tubes, shaped like closed tubes or hollow balls.
What is the structure of fullerenes?
Fullerenes are mainly made up of carbon atoms arranged in hexagons, but can also contain pentagons or heptagons.
What are some uses of fullerenes?
Fullerenes can ‘cage’ other molecules, be used as industrial catalysts, and make great lubricants.
What is Buckminsterfullerene?
Buckminsterfullerene was the first fullerene to be discovered.
What are nanotubes?
Nanotubes are tiny carbon cylinders that can conduct both electricity and thermal energy.
What is the tensile strength of nanotubes?
Nanotubes have a high tensile strength and do not break when stretched.
What is nanotechnology?
Nanotechnology is technology that uses very small particles such as nanotubes.
What are some applications of nanotubes?
Nanotubes can be used in electronics or to strengthen materials without adding much weight, such as in tennis racket frames.
What is metallic bonding?
Metallic bonding involves delocalised electrons and strong electrostatic forces between positive metal ions and shared negative electrons.
What structure do metals consist of?
Metals consist of a giant structure where the outer shell electrons are delocalised.
Why are most metals solid at room temperature?
Most metals are solid at room temperature due to very high melting and boiling points caused by strong metallic bonds.
What properties do delocalised electrons produce in metals?
Delocalised electrons produce properties such as electrical and thermal conductivity.
Why are metals good conductors of electricity and heat?
Metals are good conductors because delocalised electrons carry electrical charge and thermal energy through the structure.
What does it mean for metals to be malleable?
Malleability means that metals can be bent, hammered, or rolled into flat sheets due to the ability of atom layers to slide over each other.
Why are alloys harder than pure metals?
Alloys are harder because the different sized atoms distort the layers of metal atoms, making it more difficult for them to slide over each other.
Why are alloys used instead of pure metals for certain applications?
Alloys are used because pure metals are often too soft for certain jobs, and mixing with other metals makes them harder.
What is an example of a metallic element?
Copper is an example of a metallic element.
Why is copper suitable for electrical circuits?
Copper is suitable for electrical circuits due to its excellent electrical conductivity.
Why is an alloy of copper used for making door hinges?
An alloy of copper is used for making door hinges because it is harder and more durable than pure copper.
What are the three states of matter?
The three states of matter are solid, liquid, and gas.
What determines the state of a substance at a certain temperature?
The state depends on the strength of the forces of attraction between the particles, which is influenced by the material, temperature, and pressure.
Describe the particle arrangement in solids.
In solids, particles are held close together in fixed positions, forming a very regular lattice arrangement.
What is the movement of particles in solids?
Particles in solids vibrate about their positions and do not move from them.
How do solids respond to heat?
The hotter the solid becomes, the more the particles vibrate, causing solids to expand slightly when heated.
Describe the particle arrangement in liquids.
In liquids, particles are randomly arranged and free to move past each other, but they tend to stick closely together.
What is the movement of particles in liquids?
Particles in liquids are constantly moving with random motion.
How do liquids respond to heat?
The hotter the liquid gets, the faster the particles move, causing liquids to expand slightly when heated.
Describe the particle arrangement in gases.
In gases, the force of attraction between particles is very weak, allowing them to move freely and be far apart.
What is the movement of particles in gases?
Particles in gases move constantly with random motion and travel in straight lines.
How do gases respond to heat?
The hotter the gas gets, the faster the particles move, causing gases to either expand when heated or increase in pressure.
What is particle theory?
Particle theory is a model used to explain how particles behave in the three states of matter.
What are state symbols in chemical equations?
State symbols indicate the physical state of reactants and products: (s) for solid, (l) for liquid, (g) for gas, and (aq) for aqueous.
What does ‘aqueous’ mean?
‘Aqueous’ means ‘dissolved in water.’
What happens to a substance that does not have a definite shape or volume?
It is in the gas state.
What happens to the particles of a solid when it is heated?
The particles gain more energy and vibrate more, weakening the forces that hold the solid together.
What is the melting point?
The temperature at which particles have enough energy to break free from their positions, turning a solid into a liquid.
What is melting?
The process where a solid turns into a liquid as particles gain enough energy.
What happens to the particles of a liquid when it is heated?
The particles gain even more energy, move faster, and weaken the bonds holding the liquid together.
What is the boiling point?
The temperature at which particles have enough energy to break their bonds, turning a liquid into a gas.
What is boiling (or evaporating)?
The process where a liquid becomes a gas as particles gain enough energy.
What happens at the melting point?
So many bonds have formed between the particles that they are held in place, and the liquid becomes a solid. This is called freezing.
What happens when a liquid cools?
The particles have less energy and move around less.
What is condensing?
The process where a gas becomes a liquid as bonds form between the gas particles.
How does the strength of forces between particles affect melting and boiling points?
The stronger the forces, the more energy is needed to break them, resulting in higher melting and boiling points.
Which molecular substance is a liquid at room temperature (25 °C)?
Bromine, as it melts at -7 °C and boils at 59 °C.
What state is ethanol in at 100 °C?
Gas, as ethanol boils at 78 °C.
What state is ethanol in at 25 °C?
Liquid, as it is between its melting point (-114 °C) and boiling point (78 °C).
What state is ethanol in at 0 °C?
Liquid, as it is above its melting point (-114 °C).
What state is ethanol in at -150 °C?
Solid, as it is below its melting point (-114 °C).
