covalent bonding

Question 1

when atoms share pairs of electrons what do they form?

Answer 1

covalent bonds

Question 2

what is the definition of covalent bonding?

Answer 2

the strong electrostatic attraction between a shared pair of electrons and the protons in the nuclei

Question 3

why do simple covalent bonds not conduct electricity?

Answer 3

they dont contain free electrons

Question 4

why do simple molecular substances have a low melting and boiling point?

Answer 4

only weak intermolecular forces acting between the molecules

Question 5

the intermolecular forces are usually what compared to the covalent bonds?

Answer 5

weak

Question 6

most simple molecules are what at room temperature?

Answer 6

liquid or gas

Question 7

as the molecules increase in size what happens to the intermolecular forces?

Answer 7

they also increase

Question 8

the intermolecular forces increasing in size means what?

Answer 8

the melting and boiling points increase

Question 9

are covalent structures good or bad conductors of energy?

Answer 9

bad as there are no free ions or electrons to carry the charge

Question 10

the simple molecules contain what number of atoms?

Answer 10

fixed

Question 11

giant covalent structures contain what number of atoms?

Answer 11

a huge number( a giant lattice)

Question 12

diamond and graphite are what of carbon?

Answer 12

allotropes

Question 13

in diamond, each carbon atoms forms with how many other carbon atoms?

Answer 13

4- forming a tetrahedron

Question 14

what are the covalent bonds like in diamond?

Answer 14

identical, very strong and there are no intermolecular forces

Question 15

what are diamonds physical properties?

Answer 15

very hard, has a very high melting point and it doesnt conduct electricity

Question 16

does diamond have any freely charged particles?

Answer 16

no-therefore it cannot conduct electricity

Question 17

what is a large amount of heat required to break?

Answer 17

the lattice

Question 18

what are the atoms arrangements in silicon dioxide?

Answer 18

each oxygen atom forms covalent bonds with 2 silicon atoms and each silicon atom forms covalent bonds with 4 oxygen atoms

Question 19

what is the tetrahedron in silicon dioxide formed by?

Answer 19

one silicon atom and 4 oxygen atoms

Question 20

does silicon dioxide have covalent bonds?

Answer 20

yes lots of very strong covalent bonds

Question 21

does silicon dioxide have intermolecular forces?

Answer 21

no

Question 22

physical properties of silicon dioxide?

Answer 22

very high boiling point, insoluble in water and doesnt conduct electricity

Question 23

why is silicon dioxide cheap and what is it used for?

Answer 23

its available naturally and is used to line furnaces

Question 24

each carbon atom in graphite is covalently bonded to how many other carbon atoms?

Answer 24

3 others-forming layers of hexagons leaving one free electron per carbon atom

Question 25

how can graphite conduct electricity?

Answer 25

these free electrons migrate along the layers and are free to move and carry charge

Question 26

what are the covalent bonds like in graphite?

Answer 26

very strong

Question 27

how are the layers of ions in graphite attracted to eachother?

Answer 27

by weak intermolecular forces

Question 28

what makes graphite soft and slippery?

Answer 28

the layers can slide over eachother as they are attracted by weak intermolecular forces

Question 29

the physical properties of graphite?

Answer 29

it can conduct electricity and heat, has a high melting and boiling point and it is soft and slippery and less dense than diamond

Question 30

what makes graphite a useful material?

Answer 30

the weak intermolecular forces-make if soft and slippery

Question 31

does fullerene have a large surface area of small surface area?

Answer 31

large surface area

Question 32

what happens when non-metal atoms share pairs of electrons?

Answer 32

they get a full outer shell

Question 33

what are simple molecules?

Answer 33

a small group of atoms held together by covalent bonds

Question 34

when simple molecules boil what breaks?

Answer 34

the weak intermolecular forces

Question 35

what does electrical conductivity require?

Answer 35

charged particles that can move freely

Question 36

why do simple molecular substances never conduct electricity?

Answer 36

because the molecules are neutral

Question 37

c60 fullerene is an electrical...

Answer 37

insulator