Bonding, Structure And Properties Of Matter

Question 1

what are ions?

Answer 1

charged particles made when electrons are transferred

Question 2

talk to me about group 1 metals for ions

Answer 2

lose electrons (1+ charge)

Question 3

talk to me about group 2 metals for ions

Answer 3

lose electrons (2+ charge)

Question 4

talk to me about group 6 non-metals for ions

Answer 4

gain electrons (2- charge)

Question 5

talk to me about group 7 non-metals for ions

Answer 5

gain electron (1- charge)

Question 6

what is ionic bonding?

Answer 6

the electrostatic attraction between between oppositely charge ions. Ionic bonding occurs between positive metal ions and negative non-metal ion.

Question 7

what do dot-cross diagrams not show?

Answer 7

compound structure, or the size and arrangement of ions

Question 8

what are 3 properties of ionic compounds?

Answer 8

1: giant ionic lattice structure - electrostatic forces of attraction between oppositely charged ions act in all directions
2: high melting and boiling points - lots of energy needed to overcome the many strong bonds
3: conduct electricity only when molten or dissolved - ions free to more and carry electric charge

Question 9

what is a covalent bond?

Answer 9

a shared pair od electrons between two non-metal atoms. Covalent bonding happens in non-metal compounds and in non-metal elements

Question 10

what do molecular formulae show?

Answer 10

how may atoms of each element are in a compound

Question 11

what do dot and cross diagrams not show?

Answer 11

relative sizes of atoms or their arrangement in space

Question 12

what do ball and stick diagrams not show?

Answer 12

which atoms the electrons in the bonds come from

Question 13

what does the displayed formula not show?

Answer 13

the 3d structure

Question 14

which compunds do you need to know?

Answer 14

Hydrogen chloride
Water
Ammonia
Methane

Question 15

which elements do you need to know?

Answer 15

hydrogen
oxygen
nitrogen
chlorine

Question 16

what are 2 properties of simple molecular substances?

Answer 16

1: low melting and boiling points - mostly gases or liquids at room temperature
2: don’t conduct electricity - there are no charged particles to carry charge

Question 17

what are polymers?

Answer 17

very long chains of repeating units.
they’re usually solids at room temperature because they have relatively strong intermolecular forces (covalent)

Question 18

what is a giant covalent structure?

Answer 18

a solid containing atoms which are all bonded to each other by strong covalent bonds

Question 19

what are 2 properties of giant covalent structures?

Answer 19

1: high melting and boiling points - lots of energy needed to overcome strong covalent bonds
2: don’t conduct relectricity (with a couple of exceptions) - no charged particles to carry charge

Question 20

talk to me about diamond allotrope.

Answer 20

C atoms form 4 covalent bonds
very hard (property)
high melting point
doesn’t conduct electricity

Question 21

talk to me about graphite allotrope.

Answer 21

C atoms form 3 covalent bonds. No covalent bonds between layers
soft, slippery (property)
high melting point
conducts electricity and thermal energy

Question 22

talk to me about graphene.

Answer 22

C atoms form 3 covalent bonds
strong, light (property)
high melting point
conducts electricity (delocalised electron)

Question 23

what are fullerenes?

Answer 23

they have hollow shapes (eg, buckminsterfullerene, which is spherical and was first to be discovered)

Question 24

what are nanotubes?

Answer 24

cylindrical fullerenes used in nanotechnology, electronics and materials. They have high length to diameter ratios

Question 25

what are 4 properties of metals?

Answer 25

1: high melting and boiling points - lots of energy needed to overcome strong metallic bonds
2: good thermal conductors - energy transferred by delocalised electrons
3: good electrical conductors - delocalised electrons carry charge
4: soft and malleable - layers in metals slide over each other

Question 26

what are alloys?

Answer 26

a mixture of a metal and at least one other element. they are harder than pure metals because the new element distorts layers of metal atoms and they can’t slide past each other

Question 27

tell me about solids.

Answer 27

regular particle arrangement
fixed position but can vibrate
very close together

Question 28

tell me about liquids.

Answer 28

random arrangement
move around each other
close together

Question 29

tell me about gases.

Answer 29

random arrangement
move quickly in all directions
far apart

Question 30

what happens when a substance melts or boils?

Answer 30

substance heats up > particles gain energy > forces between particles weaken > particles break free from position

Question 31

what happens when a substance condenses or freezes?

Answer 31

substance cools down > particles lose energy > forces between particles form > particles held in position

Question 32

what is the diameter of a coarse particle (dust)?

Answer 32

2500-10000nm

Question 33

what is the diameter of a fine particle?

Answer 33

100-2500nm

Question 34

what is the diameter of a nanoparticle?

Answer 34

1-100nm (contain a few hundred atoms)

Question 35

what are 6 uses of nanoparticles?

Answer 35

1: medicines
2: cosmetics
3: sun cream
4: deoderants
5: electronics
6: catalysts

Question 36

what are the advantages to nanoparticles?

Answer 36

1: generally mroe effective than equivalent products without nanoparticles
2: smaller quantites may be needed compared to materials with ‘normal-sized’ particles

Question 37

what are the disadvantages to nanoparticles?

Answer 37

1: long-term effects on health aren’t full understood
2: could cause damage to the environment if washed away