Structure And Bonding Flashcards
What’s ionic bonding
Metal and non metal
What’s room temp
25 C
What’s covalent bonding
Non metal and non metal
Pair of electrons shared
Strong bonds
What’s metal made of
Positive atoms or ions around sea of delocalised electrons
Why can metal conduct electricity
Electrons are free to move
giant structure close packed
made up of atoms
with delocalized and free electrons
so electrons can move / flow through the metal
Difference of alloy and pure metal
Alloy- has electrons and ions but has another metal or non metal
Describe a pure metal
Has layers
= can slide across each other
= soft
Describe an alloy
Has distorted layers
= can’t slide
= hard
Describe ionic compounds structure
Giant ionic lattice
high melting point
= high boiling point
= only conduct when molten or dissolved
( ions need to be free to move )
Describe simple covalent compounds structure eg water, oxygen
Covalent bonding
= low melting points
= low boiling points
= don’t conduct electricity
Describe giant covalent compounds structure eg graphite, diamond
Giant covalent structure
= high melting points
= high boiling points
= don’t conduct electricity
= don’t dissolve
Describe diamond structure
Made of carbon
= create giant covalent lattice
Each carbon makes 4 bonds
- hard
Describe graphite structure
Made of carbon
= giant covalent
Each carbon bonds 3 times
- soft
- conducts electricity
Compare graphite and diamond
- both made of pure carbon
- graphite is made of 3 bonds
- diamond is made of 4 bonds
- graphite is soft
- diamond is hard
Compare carbon nanotubes and buckminster fullerene
- Both made of pure carbon
- Both hard
- Both have 3 carbon bonds
- buck used for lubricant
- both used for drug delivery
Describe nanotechnology
Very small
= increasing surface area
= different properties
= used for medicine drug delivery
Why can metals bend
Made of layers
= atoms can slide over each other
Why is graphite soft
Contains layers that’s slide over each other
= between layers there are only weak forces
Why is diamond hard
Each atoms forms 4 covalent bonds
= covalent bonds are very strong
Why does graphite conduct electricity
Has delocalised electrons which move through whole structure and carry the charge
Why can sodium chloride solution conduct electricity
there are ions in sodium chloride
which can move or carry the current / charge
Disadvantage of copper
copper metal is in demand
copper is expensive
Why is an alloy harder than pure metal
Atoms have different sizes
Have distorted layers
= harder for layers to slide
= elements can’t move through structure
Copper can be extracted from solutions of copper salts by adding iron
Iron more reactive
= copper is displaced
How can you tell that copper is a transition metal and aluminium is not a transition metal from the position of each metal in the periodic table?
copper is in the central block of the periodic table
whereas aluminium is in Group 3 of the periodic table
Describe the structure and bonding in metals
Giant structure of atoms/ ions with selects listed electrons
Reasons for low boiling point
- made of small molecules
= weak intermolecular forces
= little energy required to overcome intermolecular bonds
Describe alpha particle scattering experiment
- hammered gold into foil and fired tiny alpha particles at foil
- particles either went through atom or bounced off
- particles that went through proved atom mainly made of empty space not electrons
- some deflected meant centre must be positive
Why does boiling point increase
Relative mass increases
Molecules become larger
= stronger intermolecular forces
= more energy required to overcome intermolecular forces
Describe reactivity of halogens
As you go down become further from nucleus
= nucleus has less attraction to outer shells
= electron gained less easily
Adv of using burette
Can measure variable volumes
Can add solution drop by drop
Adv of using a burette
Can add solution drop by drop
Can measure variable volumes
Reason for high boiling point
giant structure
(with) strong (electrostatic) forces of attraction between (oppositely charged) ions
(so) large amounts of energy are needed to break the bonds / forces
Describe a fullerene
Tubular or hollow spherical molecules held together by covalent bonds
3 covalent bonds per atom
= 1 spare electron per carbon atom
= electrons can flow through structure
= can conduct electricity
