covalent bonding and halogens Flashcards
definition of covalent bonding
electrostatic attraction between shared electrons and a nuclei
what type of atoms do covalent bonding associate with
non-metals
what is the relative melting point of covalent bonds
low
why is the melting point low for covalent bonds
- breaking IMF
- IMFs are very weak and need little energy to break
are covalent bonds able to conduct electricity
no, no charged particles are ever able to move
how is mass related to melting point
bigger mass = stronger IMF which means more energy needed to break IMFs so higher melting point
example of giant covalent structures
graphite, diamond
do giant covalent have high melting points
yes as you are breaking covalent bonds and they are very strong and need a lot of energy to break
structure of graphite
- layers of carbon atoms bonded together
- each carbon forms 3 bonds and each atom has an electron left over so is delocalised
can graphite conduct electricity
yes as one electron is delocalised so can move
what can graphite be used as
lubricant
why can graphite be used as lubricant
- between layers are IMF
- IMF are very weak and can be broken very easily
- layers are able to slide over each other
- graphite is very slippery and can be used as lubricant
structure of diamond
forms a pyramid ( tetrahedron ) each C bonded to 4 others
can diamond conduct electricity
no as all electrons were used in bonds
does diamond have a higher or lower mpt than graphite
higher because more bonds are broken so even more energy is needed
how many electrons do Halogens want to gain a full outer shell
1 e
describe the trend of mpt going down the group the halogens
mpt increases because molecules get bigger so more IMF and more energy is needed
describe the trend of colour going down the group of Halogens
gets darker
describe the trend of reactivity going down the group of Halogens
reactivity decreases because
- atoms want gain an electron
- atoms get bigger going down the group and bigger atoms means greater distance between extra e and nucleus
- less electrostatic attraction
- less reactive
give two experiments to prove that reactivity decreases
- reacting each metal with MG
- displacement reactions
what does a pale green solution indicate after displacing halogens
chlorine has been displaced
what does a orange solution indicate after displacing halogens
bromine has been displaced
what does a purple solution indicate after displacing halogens
iodine has been displaced
what colour is flourine
pale yellow gas
what colour is chlorine
green gas
what colour is bromine
brown liquid
what colour is idodine
dark grey solid
what colour is astatine
black solid
what is the test for chlorine
place a damp piece of blue litmus paper in the chlorine and it will bleach it white
