covalent bonding (4.2)

Question 1

what happens when non metal atoms bond

Answer 1

they share a pair of electrons to get a full outer shell (covalently bond)

Question 2

covalent bond definition

Answer 2

the electrostatic force of attraction between protons in 2 nuclei and a shared pair of electron between them

Question 3

what does the shared per of electrons do

Answer 3

pull the nuclei of the atoms closer together

Question 4

is a covalent bond a strong or weak attraction

Answer 4

very strong

Question 5

what is a small group of atom held together by a covalent bond called

Answer 5

a simple molecule

Question 6

what is an example of a simple molecular substance

Answer 6

C60 fullerine

Question 7

properties of a simple molecular substance

Answer 7

low boiling points
weak intermolecular forces
strong covalent bonds
don’t conduct electricity

Question 8

why do simple molecular molecules have low boiling points

Answer 8

due to their weak intermolecular forces
when simple molecular substances boil, the weak intermolecular forces break

Question 9

why can’t simple molecular substances conduct electricity

Answer 9

its molecules are neutral

Question 10

what is C60 fullerine

Answer 10

a simple molecular substance made of 60 carbon atoms in a ball

Question 11

c60 fullerine properties

Answer 11

-low boiling point, but not as low as other molecules due to its high molecular mass
-soft and slippery because the molecules can roll over each other easily
-electrical insulator because the molecules are neutral

Question 12

what is a giant covalent substance

Answer 12

a solid with a very high melting point, with atoms that are linked by strong covalent bonds

Question 13

examples of giant covalent substances

Answer 13

diamond
graphite
silicone dioxide

Question 14

what is diamond

Answer 14

a giant covalent structure, which is a form of pure carbon arranged into a giant lattice

Question 15

structure of diamond

Answer 15

-every carbon atom makes 4 covalent bonds
-tetrahedral shape
-strong, grid-like arrangement

Question 16

properties of diamond

Answer 16

-sublimes at a very high temperature due to strong covalent bonds, lots of bonds in the giant lattice, and lots of energy is required to break all the bonds
-one of the hardest substances, so used in cutting
-cannot conduct electricity because there is no freely-moving charged particles
-all the atoms are neutral
-all the electrons are stuck inside an atom or a bond

Question 17

what is graphite

Answer 17

a giant covalent structure, which is a form of pure carbon arranged into a giant lattice

Question 18

structure of graphite

Answer 18

-layers of hexagonal carbon stoms
-every carbon makes 3 covalent bonds
-weak intermolecular forces between layers
-delocalised electrons inside each layers

Question 19

properties of graphite

Answer 19

-sublimes at a very high temperature due to strong covalent bonds, lots of bonds in the giant lattice, and lots of energy is required to break all the bonds
-soft and slippery bc the layers can slide easily, so its used as a solid lubricant
-conducts electricity due to delocalised electrons can move freely

Question 20

what is silicon dioxide

Answer 20

a giant covalent structure which is known as silica

Question 21

structure of silicon dioxide (silica)

Answer 21

-every silicon atom makes 4 covalent bonds
-every oxygen atom makes 2 covalent bonds
-tetrahedral shape (like diamond)
-strong, grid like arrangement

Question 22

properties of silica

Answer 22

similar properties to diamond due to its similar bonding and structure
however its much less expensive because its much less rare.