Structure, Bonding & Properties of Matter Flashcards
How are ions made?
Made when electrons are transferred
What are ions?
Charged particles
When atoms lose or gain electrons to form ions, what are they trying to do?
To get a full outer shell (stable electronic structure)
When metals form ions, what happens to their electrons and what type of ions do they form?
They lose electrons from their outer shell to form positive ions
When non-metals form ions, what happens to their electrons and what type of ions do they form?
They gain electrons into their outer shell to form negative ions
What does the charge on the ion represent?
Number of electrons lost or gained
Explain ionic bonding
- Non-metal gains electrons = negatively charged ion
- Metal atom loses electrons = positively charged ion
- Opposite charged ions are strongly attracted to one another by electrostatic forces
What the structure of an ionic compounds called?
Giant ionic lattice
How ions arranged in a giant ionic lattice? (forces?)
They’re closely packed with very strong electrostatic forces of attraction between oppositely charged ions - in all directions
Name 3 properties of ionic compounds
- High melting points
- High boiling points
- Dissolve easily in water
When ionic compounds melt, what can they do and why?
Carry electric current bc ions are free to move
Why do ionic compounds have high melting/boiling points?
Due to MANY strong bonds between ions = takes a lot energy to overcome this attraction (electrostatic forces)
Draw the structure of sodium chloride
See mind map
What is covalent bonding?
When non-metals bond together: share a pair of electrons to make covalent bonds
Why are covalent bonds very strong?
Positively charged nuclei of bonded atoms are attracted to the shared pair of electrons by electrostatic forces
Atoms only share electrons in their…
outer shells (highest energy levels)
What does each covalent bond provide for each atom?
1 extra shared electron
Atom involved generally makes enough covalent bonds…
to fill up its outer shell
Draw the covalent bonds for water
See mind map
Draw the covalent bonds for water in this form Cl-Cl
See mind map
Draw the covalent bonds for ammonia
See mind map
Draw the covalent bonds for ammonia in this form Cl-Cl
See mind map
Draw the covalent bonds for hydrogen
See mind map
Draw the covalent bonds for hydrogen in this form Cl-Cl
See mind map
Draw the covalent bonds for hydrogen chloride
See mind map
Draw the covalent bonds for hydrogen chloride in this form Cl-Cl
See mind map
Draw the covalent bonds for methane
See mind map
Draw the covalent bonds for methane in this form Cl-Cl
See mind map
Draw the covalent bonds for oxygen
See mind map
Draw the covalent bonds for oxygen in this form Cl-Cl
See mind map
Usually substances containing covalent bonds, have what kind of structure?
Simple molecular structures
For covalent compounds with a simple molecular structures, what the intramolecular forces like?
Very strong (covalent bonds)
For covalent compounds with a simple molecular structures, what the intermolecular forces like?
Very weak (forces of attraction between molecules)
Why do simple molecular substances have low melting/boiling points?
Feeble intermolecular forces need to be broken (NOT covalent bonds) = molecules are easily parted (little energy to overcome)
What states are simple molecular substances at room temperature?
Most are gases or liquids
Why is it that as a simple molecular substance gets larger, the melting/boiling points increases?
Strength of intermolecular forces increases = more energy needed to break them
Why don’t simple molecular substances conduct electricity?
Because they aren’t charged = no free electrons or ions
In giant covalent structures (macromolecules), how are all atoms bonded together?
By strong covalent bonds
Why do macromolecules have very high melting/boiling points?
Lots of energy is needed to break covalent bonds between atoms
Why don’t macromolecules conduct electricity?
Don’t contain charged particles = don’t conduct electricity (not even when molten)
How many covalent bonds can carbon have?
4
Why is diamond really hard?
Giant covalent structure - made up of carbon atoms that form four covalent bonds = makes it really hard
Why does diamond have a really high melting point?
Strong covalent bonds take a lot of energy to break
Why doesn’t diamond conduct electricity?
Because it has no free electrons/ions
Describe the structure of graphite
Carbon atoms forms three covalent bonds = creating sheets of carbon atoms arranged in hexagons
Why is graphite an ideal lubricating material?
- Aren’t any covalent bonds between layers - only held together with weak forces
- Layers can slide over each other = graphite slipperily
Why doe graphite have a high melting point?
Covalent bonds in layers need a lot of energy to break
Why can graphite conducts electricity and thermal energy?
Only three out of each carbon’s four outer electrons are used in bonds = carbon atoms has one electron that’s delocalised (free) and can move THROUGH whole structure
What is graphene?
Sheet of carbon atoms joined together in hexagons (sheet is one atom thick)
What do metals consist of?
Giant structures of atoms arranged in a regular pattern
Explain metallic bonding
- Electrons in outer shell are delocalised
- Strong forces of electrostatic attraction between the positive metal ions and shared negative electrons
- These forces of attraction hold the atoms together in a regular structure (known as metallic bonding)
What produces the properties of metals?
Delocalised electrons in metallic bonds
What does the condition of a metal depend on?
The ability of electrons to move through the metal
Why are metals malleable?
Layers of atoms can slide over each other
Why are metals solid at room temperature?
Electrostatic forces between metal atoms and delocalised electrons are very strong - lots of energy needed to broken
∴ Most have very high melting and boiling points
Why are metals a good conductor of electricity and heat?
Delocalised electrons carry electrical current and thermal
energy through whole structure
What are intermolecular forces?
Are forces that exist between molecules
What are intramolecular forces?
Are the forces that hold atoms together within a molecule
What are fullerenes?
Molecules of carbon, shaped like closed tubes or hollow balls
What is the structure of fullerene like?
Made up of hexagon rings of carbon atoms
What can fullerenes be used for? Name 4 things
- Deliver a drug into body
- Catalysts
- Lubricants
- Nanotubes
How can fullerenes be used to deliver a drug into body?
They ‘cage’ other molecules = structure forms around another atom/molecule
How can fullerenes be used as catalysts?
Individual molecules could be attached to fullerenes
Why would fullerenes help make great industrial catalysts?
Because they have a large surface area
Name 3 properties of nanotubes
- Ratio between length and diameter of nanotubes = very high
- Have high tensile strength (don’t break when stretched)
- Conduct both electricity and thermal energy
What can nanotubes be used for? Name 2 things
- In electronics
2. Strengthen materials without adding much weight E.g. tennis racket frames
How large a nanoparticles? (length and no. of atoms)
1-100nm, contain only a few hundred atoms
Nanoparticles have a…
Large surface area to volume ratio
As particles decrease in size…
size of surface area increases in relation to their volume
What can having large surface area to volume ratio cause for nanoparticles?
For them to have different properties for the same material in bulk
Why are some people worried about products containing nanoparticles?
Bc they’ve been made available before effects on human health have been investigated properly = we don’t know long term impacts on health will be
