BONDING

Question 1

Electron sea model

Answer 1

the electron sea model states that metal is made up of a lattice of positively charged ions or cations , surrounded by a sea of delocalised electrons.
the delocalised electrons carry charge and they are allowed to move freely, so metals can conduct electricity.

Question 2

metallic bonding

Answer 2

the electrostatic attraction between cations and delocalised electrons.
the stronger the attraction=stronger the bond.

Question 3

why are metals malleable and ductile

Answer 3

metals are malleable and ductile because the layers of cation can slide over each other without breaking the metallic bonds.

Question 4

why does melting point increases across a period

Answer 4

because as we go across the period, lattice with highly charged cations are formed, so more electrons are delocalised per cation and attraction increases.

Question 5

note

Answer 5

metals only delocalise the electrons which are present in their valence shell.

Question 6

why does melting point decreases down a group

Answer 6

because as we go down, the size increases-more distance between delocalised electrons and the cations-weaker force of attraction- lower melting point.

Question 7

common anions

Answer 7

p-3 = phosphide
n-3 = nitride
s-2 = sulphide

Question 8

common exam question: explain how mgo is formed from its atoms

Answer 8

two electrons are transferred from 1 oxygen atom to 1 magnesium atom.

Question 9

perfect ionic model

Answer 9

ionic compounds are composed of perfectly spherical cations and anions arranged in a lattice.