Bonding and Structure

Question 1

how do you know the number of protons in an atom?

Answer 1

atomic number

Question 2

how do you know the number of neutrons in an atom?

Answer 2

mass number - atomic number

Question 3

how do you know the number of electrons in an atom?

Answer 3

atomic number

Question 4

what is the charge for group 1 elements?

Answer 4

+1

Question 5

what is the charge for group 2 elements?

Answer 5

+2

Question 6

what is the charge for group 3 elements?

Answer 6

+3

Question 7

what is the charge for group 5 elements?

Answer 7

-3

Question 8

what is the charge for group 6 elements?

Answer 8

-2

Question 9

what is the charge for group 7 elements?

Answer 9

-1

Question 10

what is the ion for silver?

Answer 10

Ag+

Question 11

what is the ion for copper?

Answer 11

Cu²+

Question 12

what is the ion for iron?

Answer 12

Fe²+ / Fe³+

Question 13

what is the ion for lead?

Answer 13

Pb²+

Question 14

what is the ion for zinc?

Answer 14

Zn²+

Question 15

what is an anion?

Answer 15

a negative ion

Question 16

what is a cation?

Answer 16

a positive ion

Question 17

why do ions have high melting and boiling points?

Answer 17

strong electrostatic forces of attraction which require lots of energy to overcome

Question 18

how are ions formed?

Answer 18

when a metal and non-metal reacts

Question 19

why can ions conduct electricity when dissolved or molten?

Answer 19

the ions are free to move and can carry a charge

Question 20

why can’t ions conduct electricity as solids?

Answer 20

the ions are not free to move

Question 21

how is a covalent bond formed?

Answer 21

when atoms (usually 2 non-metals) share pairs of electrons

Question 22

why do compounds with giant ionic lattices have high melting and boiling points?

Answer 22

strong electrostatic forces of attraction which require lots of energy to overcome

Question 23

why do simple molecular compounds have low melting and boiling points?

Answer 23

weak intermolecular forces of attraction which require little amount of energy to overcome

Question 24

why do giant covalent structures (like diamond and graphite) have such high melting and boiling points?

Answer 24

strong covalent bonds which require a lot of energy to overcome

Question 25

can diamond conduct electricity? and why?

Answer 25

no diamond is an insulator because it has no delocalised electrons

Question 26

can graphite conduct electricity? and why?

Answer 26

yes graphite is a conductor because it has delocalised electrons which can carry a charge through the structure

Question 27

can buckminsterfullerene's conduct electricity? and why?

Answer 27

no C60 is an insulator because although it has delocalised electrons, these electrons cannot move from molecule to another

Question 28

what is the strength of diamond?

Answer 28

very strong and hard

Question 29

what is the strength of graphite?

Answer 29

soft and brittle

Question 30

what is the strength of C60?

Answer 30

soft

Question 31

why do covalent compounds not conduct electricity

Answer 31

because they are neutral and there are no charged particles (ions) to move and carry a charge

Question 32

what is an alloy?

Answer 32

a mixture of a metal and one or more elements - usually other metals or carbon

Question 33

what is an allotrope?

Answer 33

different forms of the same element (for example C60, diamond and graphite are 3 allotropes of carbon)

Question 34

how can metals conduct electricity?

Answer 34

they have delocalised electrons that can carry a charge and move around the metal ions

Question 35

true or false? metals are malleable. if so why?

Answer 35

true. metals can be hammered into thin sheets without breaking. this is due to the electrostatic attractions within the structure

Question 36

why are alloys stronger than pure metals?

Answer 36

because they contain atoms of different sizes which distorts the regular arrangements of atoms. this makes it more difficult for the layers to slide over each other

Question 37

what are the electrostatic attractions of metallic bonding?

Answer 37

strong electrostatic attraction between sea of negative delocalised electrons and positive metal ions

Question 38

what is a compound?

Answer 38

2 or more different elements chemically bonded together