Bonding, structure and properties of matter (1)

Question 1

What is an ion

Answer 1

a charged particle made when an atom gains or looses electrons

Question 2

ionic bonding-
properties-

Answer 2

a metal and non-metal react and transfer electrons
the oppositely charged ions are held together by strong electrostatic forces

Question 3

ionic compounds-
properties-

Answer 3

ionic compounds have a giant lattice structure

properties- high melting and boiling points due to electrostatic forces
can carry an electrical charge when melted or
dissolve in water as the ions can carry charge

Question 4

Covalent bonding-
simple covalent substance properties-

Answer 4

two non-metals bonding by sharing electrons
the positively charged nuclei are attracted to the shared electrons so there are strong electrostatic forces

properties- low melting point as intermolecular forces are weak
don’t conduct electricity

Question 5

Polymers

Answer 5

Long chains of repeating units held together by covalent bonds
intermolecular forces weaker than ionic or giant molecular substances but stronger than simple molecular substances

Question 6

Giant covalent structures examples (4)-

Answer 6

Diamond- each carbon atom forms four covalent bonds, making the substance incredibly hard

graphite- each carbon atom forms three covalent bonds creating layers of hexagons, and has one delocalised electron so conduct electricity
made of layers with weak forces so they slide off easily, making graphite good for pencils and lubricants

graphene- a single layer of graphite

silicon dioxide- (sand) made of silicon and oxygen

Question 7

Fullerenes

Answer 7

molecules of carbon in pentagon or hexagon shapes forming enclosed shapes like nanotubes or Buckminster balls
They can cage other molecules so are used to administer drugs in the body
They have a huge surface area so make good catalysts

Question 8

Metallic bonding-
metal properties-

Answer 8

Metal atoms being attracted to delocalised electrons
properties- solid, conductive, malleable, high melting/boiling point because of electrostatic forces

Question 9

What is an alloy

Answer 9

a mixture of metals or mixing a metal with another substance to make the metal more solid, as the molecules are different sizes so can’t slide over each other as easily

Question 10

what is sublimation

Answer 10

solid going straight into a gas

Question 11

coarse particles-
fine particles-
nanoparticles (properties)-

Answer 11

coarse particles- diameter between 2500nm and 10000nm
fine particles- diameter between 100nm and 2500nm
nanoparticles- diameter between 1nm and 100nm (extremely high surface area to volume ratio)

Question 12

Uses of nanoparticles

Answer 12

nanomedicine (using fullerenes to deliver medicines)
conduct electricity so used in computer chips
silver nanoparticles have antibacterial processes, so can be used in surgical masks, wound dressings and deodorants
used in moisturisers to make them less oily
suncreams

Question 13

Risks of nanoparticles

Answer 13

They are a new science so affect on the body is not yet fully understood

Question 14

How do metals conduct electricity

Answer 14

Delocalised electrons can carry charges through the structure