Bonding, Structure And The Properties Of Matter Flashcards
What’s it called when a gas becomes a solid? - Properties of Matter
Sublimation
What is the relationship between melting point, boiling point and forces between particles? - Properties of Matter
The stronger the forces between particles, the more energy is required to break bonds
What structure does an ionic compound have? S+B
They form a regular ionic lattice, as the positive and negative ions are attracted to one another.
How is an ionic lattice held together? S+B
Strong electrostatic forces of attraction
What limitations are there to 2-D and 3-D ionic models? S+B
2-D: only shows ionic arrangements in 1 layer
3-D: presents lots of space between ions which there isn’t
How do ionic lattices melt and boil? - S+B
Energy must be transferred to an ionic substance (in the form of thermal) in order to overcome the electrostatic attraction between ions. The more energy needed, the higher the melting/boiling point
A substance can conduct electricity when? - S+B
If they contain charged particles (ions or electrons) which are free to move
When can ionic substances conduct electricity? - S+B
When it has melted into a liquid or is molten or is dissolved in an aqueous solution
How big are atoms? - S+B
-10
1x10
What diagrams shows how covalent bonding takes place? - S+B
Dot + cross diagrams, structural formula (lines showing the no. of bonds)
What are the forces like between molecules of intermolecular forces?
Weak, don’t require much energy to break
What are giant covalent substances? - S+B
A substance which contains many atoms joined by covalent bonds
What type of boiling + melting points do giant covalent substances have? S+B
They are solid at room temp, and therefore have high melting and boiling points
Can giant covalent substances conduct electricity (+ name exception) - S+B
Most giant covalent substances cannot carry charge as they have no free charged particles. Graphite is an exception as it has delocalised electrons.
What element are both diamond and graphite made from? - S+B
Carbon
How many carbon atoms is a carbon atom bonded to in diamond and graphite? - S+B
Graphite - every C is bonded to 3 C
Diamond - every C is bonded to 4 C
What does graphite’s 3 bond structure mean can happen? - S+B
Graphite can carry electrical charge as it has one delocalised electron from each atom.
Why is graphite slippery? - S+B
It has layers which fit over the top of one another. The forces between layers are weak, and can therefore be used as a lubricant
What are fullerenes + 2 examples? - S+B
Fullerenes are carbon molecules that are hexagonal
Nanotubes and buckminsterfullerenes
What are nanotubes used for and why are they ideal for this? - S+B
Useful in electronics and nanotechnology due to their strength and their ability to conduct electricity
What is a polymer? - S+B
A large molecule formed from many identical smaller molecules known as monomers
What properties do polymers have? (IM Forces) - S+B
Strong IM Forces, mean polymers melt at high temperatures than smaller molecules. Solids at room temp
Describe metallic bonding - S+B
Atoms are arranged regularly, with each atom relinquishing electrons from their outer shells, which are delocalised and allow metals to carry charge
What is the term for the outer electrons in metallic bonds? - S+B
The sea of delocalised electrons
What properties do metals have? - S+B
Good electrical conductors due to delocalised electrons, also good thermal conductors. High melting + boiling due to strong bonding
Why are alloys stronger than pure metals? - S+B
Different sized atoms disrupt the smooth, regular structure of the metal, making it harder
When covalently bonded structures are heated, what is broken in the structure? - S+B
The intermolecular forces are broken, not the bonds between atoms
What is the size of a nanoparticle? - S+B.
1x10^-9 metres
What advantage do nanoparticles have compared to the same material in bulk? - S+B
They have a larger SA:V Ratio than bulky particles. This means they take part in reactions quicker
How can nanoparticles be used? - S+B
As catalysts
In medical treatments
In electronics
In deodorants
Name 2 uses of buckminsterfullerenes - S+B
Carrying drugs into the body
As a lubricant as the balls can easily roll over surfaces
What risks are there with nanoparticles? - S+B
Potential to be inhaled, and toxic substances could bind to them when inhaled
What 4 chemical substances represent the four types of structure?
Salt, methane, sand and copper
What are the properties of salt?
High MPt/ BPt, Solid, Composed of Metal and Non-Metal, good electrical conductivity when melted or dissolved in water.
What are the properties of methane?
Low MPt/ BPt, Gaseous, composed of Non-metals, non conductor of electricity.
What are the properties of sand?
High MPt/ BP, Solid, composed of Non-metals, Non conductor
What are the properties of copper?
High MPt/ BPt, Solid, Metal, good conductor when solid.
What category does salt fall under?
Giant ionic substance
What category does copper fall into?
A metal substance
What category does methane fall into?
Simple covalent. This means it has strong covalent bonds between molecules but weak intermolecular forces
What category does sand fall into?
Mainly composed of silica so is a giant covalent, means it has strong covalent bonds and weak intermolecular forces that hold together the structure
What type of bonding is in carbon allotropes?
Covalent bonding
What structure is formed through covalent bonding?
Giant covalent lattice
How many covalent bonds are present in the carbon allotrope diamond?
4 covalent bonds
Describe the arrangement of atoms in a diamond.
Tetrahedral giant lattice structure
Give a property and use of diamond.
Very strong, used in drills in dentistry
How many covalent bonds are present in graphITE?
3 covalent bonds
Describe the arrangement of atoms in graphITE.
Layered hexagonal structure
Why can graphITE be used as a lubricant?
The layers of hexagonal structure can slide over each other as it is delocalised electrons, not any bonds, that hold the layers together.
Give a property and use of graphITE.
Electrical conductor- delocalised electrons
Pencils and electrolysis.
How many covalent bonds are present in graphINE?
3 covalent bonds.
Describe the arrangement of atoms in graphINE.
Single layered Hexagonal structure
Give a property and a use of graphINE.
Transparent, strong super conductor- used in technology.
How many covalent bonds are present in Buckminster Fullerenes
4 bonds (double bonds)
What types of elements are involved in ionic bonding?
Metals and non metals
Describe the structure in an ionic bong?
Giant lattice
Describe the melting and boiling pints of ionic bonds
High MPt and Bpt
What atoms are involved in metallic bonding?
Metal atoms
Describe the structure of metallic bonds.
Giant lattice
Describe the melting and boiling pouy of metallic bonds
High MPt and BPt
Which atoms are involved in SIMPLE covalent molecules?
Non metal only
Describe the melting and boiling point of SIMPLE covalent molecules
Low MPt and BPt
What atoms are involved in giant covalent bonding?
Non metal atoms (mainly carbon)
Describe the melting and boiling point of giant covalent bonds
High MPt and BPt
Why do giant covalent structures have high melting points, but simp covalent molecules have low melting points?
Because more energy is needed to overcome the number of bonds in a giant covalent STRUCTURE than in a simple covalent MOLECULE.
What’s an example of giant covalent structures?
Diamond and graphite.
What is a fullerene?
A cylindrical or spherical structure
Give a property and use of buckminster fullerenes.
- better lubricant than graphite
- good catalyst
- high surface area to volume ratio
- can be used in pharmaceutical delivery as it protects the body from toxins in the treatment by only delivering the medication to the affected area and preventing the meds acting elsewhere.
Why do elements bond?
To complete their outer electron shell by either gaining or losing electrons.
Why are sodium and chlorine dangerous unconfined but can be used as table salt when combined?
Because they haven’t yet gained a full outer shell and are therefore still reactive. When combined, the ionic bond they form provides both elements with full outer shells- unreactive
What are the 4 properties of ionic compounds?
Sharp edges, high melting points, soluble and conducts electricity when molten (liquid) or dissolved (aqueous)
What type of forces do ionic compounds have?
Electrostatic (hard to break)
