C3

Question 1

three states of matter

Answer 1

solid, liquid and gas

Question 2

solid

Answer 2

arrangement of particles with a fixed shape and volume, they cannot be compressed

Question 3

liquid

Answer 3

arrangement of particles with a fixed volume but they can flow and change shape

Question 4

gas

Answer 4

arrangement of particles with no fixed shape or volume, they can be compressed easily

Question 5

compound

Answer 5

a substance made of two or more elements chemically bonded together

Question 6

covalent bonding

Answer 6

bonding between non-metals only, in which electrons are shared

Question 7

ionic bonding

Answer 7

bonding between metals and non-metals, in which electrons are transferred

Question 8

positive ion

Answer 8

an atom that loses one or more electrons and gains a positive charge

Question 9

negative ion

Answer 9

an atom that gains one or more electrons and gains a negative charge

Question 10

electrostatic attraction

Answer 10

the strong force that holds ions together

Question 11

giant lattice

Answer 11

the arrangement of ions in ionic bonding results in this structure

Question 12

NaCl

Answer 12

sodium chloride

Question 13

MgCl₂

Answer 13

magnesium chloride

Question 14

Ca(OH)₂

Answer 14

calcium hydroxide

Question 15

simple molecules

Answer 15

small molecules in which atoms are held together by covalent bonds

Question 16

giant covalent structures

Answer 16

giant structures where atoms are held together by an array of covalent bonds

Question 17

intermolecular forces

Answer 17

weak forces between covalently bonded molecules that must be broken when simple substances melt or boil

Question 18

diamond

Answer 18

an allotrope of carbon in which all of the carbon atoms are bonded to 4 others resulting in an extremely strong structure

Question 19

silicon dioxide

Answer 19

a giant covalent structure very similar to diamond but made from silicon and oxygen instead of carbon

Question 20

graphite

Answer 20

an allotrope of carbon that has hexagonal sheets of carbon with weak attractive forces between the layers

Question 21

fullerenes

Answer 21

an allotrope of carbon in which the carbon form cage like structures

Question 22

delocalised electrons

Answer 22

electrons not linked with a particular ion that are free to move through a structure

Question 23

graphene

Answer 23

a single sheet of carbon atoms (like one layer of graphite)

Question 24

crystals

Answer 24

metal atoms build up layer upon layer to form these structures

Question 25

alloys

Answer 25

a mixture of metals, typically much harder than metal atoms alone

Question 26

How can you use the periodic table to help you remember charges on ions?

Answer 26

``` Look at the group number: Group 1 form +1 ions Group 2 = +2 Group 3 = +3 Group 4 = don't form ions Group 5 = -3 Group 6 = -2 Group 7 = -1 Group 0 don't form ions ```

Question 27

What are the properties of simple molecular substances?

Answer 27

Gases, liquids (with low boiling points) or solids (with low melting points), usually non conductors.

Question 28

Why do simple covalent compounds have low melting and boiling points?

Answer 28

They have weak forces of attraction between their molecules that take little energy to overcome.

Question 29

What are the properties of giant covalent structures?

Answer 29

Solids with very high melting and boiling points.

Question 30

Why do giant covalent structures have high melting points?

Answer 30

To melt you need to break STRONG covalent bonds between the atoms which requires a lot of energy.

Question 31

Why do metals conduct electricity?

Answer 31

They have delocalised electrons which can flow when an electric field is applied across it.

Question 32

Why are metals malleable?

Answer 32

Layers of cations in a metal lattice can slide over each other when a force is applied. The layers of ions are held together by the delocalised electrons.

Question 33

Do ionic compounds conduct electricity?

Answer 33

Yes, but only when molten or in solution. The ions are then free to move. In solid ions have fixed positions and can not move.