Bonding

Question 1

Covalent bond

Answer 1

-strong electrostatic force of attraction between shared pair of electrons and nuclei

Question 2

ionic bond

Answer 2

strong electrostatic force of attraction between oppositely charged ions

Question 3

metal bond

Answer 3

strong electrostatic force of attraction between positive ions and sea of delocalised electrons

Question 4

isoelectric

Answer 4

-two species that have the same electronic structure
-for example potassium and argon are isoelectric as potassium becomes 2.8.8 which is the same as argon
-it does not have to be a noble gas

Question 5

why does diamond have a high melting point

Answer 5

-diamond is giant covalent
-it has lots of strong covalent bonds
-it takes lots of energy to break these bonds so it has a high melting point

Question 6

why can graphite conduct electricity

Answer 6

-only three out of carbon’s four electrons are used in bonds
-each carbon atom has one electron that is delocalised and can move
-graphite is a non-metal that conducts electricity

Question 7

why can graphite be used as a lubricant

Answer 7

-it has layers of carbon atoms
-the layers are held together weakly by intermolecular forces, so are free to slide over each other
-makes graphite soft and slippery

Question 8

why does water have a low boiling point

Answer 8

-it has a simple molecular structure
-the water molecules are held together by weak intermolecular forces
-little energy is needed to break these forces, hence water has a low boiling point

Question 9

why can ionic compounds conduct electricity when molten or in solution

Answer 9

-when solid, ionic compounds do not conduct electricity as the ions are not able to move around
-when an ionic compound is dissolved the ions separate and are able to move in the solution
-when an ionic compound melts, the ions are also able to move so the compound can conduct electricity

Question 10

why can metals conduct eledctricity

Answer 10

-the delocalised electrons are able to move through the structure
-this means metals can conduct electricity

Question 11

why can metal conduct heat well

Answer 11

-The delocalised electrons are able to move through the structure
-The movement of electrons means energy can be transferred quickly through the material, so metal are good conductors of heat

Question 12

why are metals malleable

Answer 12

-the layers of ions in a metal can slide over each other
-this makes metal malleable

Question 13

why can ionic bonds dissolve in water

Answer 13

-it has polar molecules(has positive and negative ions
-the H+ attracts the negative ion and the O- attracts the positive ion
-this rips the ion apart