metallic bonding

define metallic bonding

chemical bonding that occurs between metal atoms in a metallic substance

describe what a metallic bond consists of

consists of a lattice of positively charged ions surrounded by a sea of delocalised electrons

• valence electrons of metal ions delocalised → free to move throughout crystal lattice → results in a sea of electrons

→ results in a strong electrostatic force of attraction between metal ions and electrons → forms network of metallic bonds

describe and explain the factors which affect the strength of a metallic bond

size of charge

• greater difference in charge = stronger attractive force

size of metal ion

• smaller size = stronger bond:  smaller radius = shorter distance between positive nucleus and negative electrons → stronger attraction force

number of mobile electrons per atom

• more mobile electrons = more can contribute to the sea of electrons holding the lattice together → stronger negative charge

describe and explain the properties of metallic structures

high mp + bp

• positive metal ions strongly attracted to delocalised electrons → stronger electrostatic force requires more energy to break } more electrons = higher mp + bp

conduct electricity + heat

• contain delocalised electrons which are free to move and carry charge

insoluble in all solvents (apart from liquid metals)

• metals can’t dissolve since metallic bonds are very strong