1.44-1.51 covalent bonding

Question 1

when is a covalent bond formed

Answer 1

A covalent bond is formed between two non-metal atoms by sharing a pair of electrons in order to fill the outer shell

Question 2

covalent bonds in terms of electrostatic attractions

Answer 2

Strong attraction between the shared pair of Electrons and the Nuclei of the atoms involved

Question 3

explain why substances with a simple molecular structures are gases or liquids, or solids with low melting and boiling points

Answer 3

for example,Carbon dioxide (CO2) has a simple molecular structure. This just means that it is made up of molecules.

Within each molecule are atoms bonded to each other covalently.
These covalent bonds inside the molecules are strong.

but, between the molecules are weak forces of attraction that require little energy to break.

Question 4

why ass mass increases does the melting/boiling point increase of simple molecular structures

Answer 4

larger molecules have more attractions which must be overcome.

Question 5

explain why substances with giant covalent structures are solids with high melting and boiling points

Answer 5

fex. Diamond has a high melting point because it is a giant covalent structure with many strong covalent bonds that require a lot of energy to break.

Question 6

describe the structure of graphite

Answer 6

-graphite can conduct electricity because the delocalised electrons are free to move

-weak forces of attraction between the layers. These layers can easily slide over each other.

-soft and slippery used as a lubricant

Question 7

describe the structure of a diamond

Answer 7

-Diamond is extremely hard because it is a giant 3D lattice- covalent structure with many strong covalent bonds.

-used in high speed cutting tools, eg diamond-tipped saws

Question 8

describe the structure of C60 fullerene

Answer 8

-simple molecular structure
- The molecule of 60 carbon atoms has weak intermolecular forces of attraction between them which take little energy to overcome
-low melting point, and it is soft
-cannot conduct electricity.

Question 9

covalent compounds usually conduct electricity, true or false

Answer 9

False.

Electric current is a flow of charged particles that can move.

Covalent compounds do not conduct electricity