metallic and ionic bonds Flashcards
Metallic bonding structure:
Positive ions surrounded by a ‘sea’ of delocalised electrons.Strong attraction between ions and delocalised electrons.
Giant Ionic Structure:
Regular 3D arrangement of positive and negative ions.Strong electrostatic attraction between positive and negative ions
Simple covalent structure:
Discrete molecules with weak forces between molecules.Strong bonds between atoms, electrons are shared
Giant covalent structure:
Repeating 3D or 2D structures with strong bonds between atoms. Strong bonds between atoms and electrons are shared.
Ionic bonding properties:
High melting points, always solid at room temp
Conduct electricity only when molten and in solution
brittle
Metallic Bonding properties:
Mostly high melting points, almost all are solids at room temp
Conduct electricity
Malleable, ductile
conducts heat
lustre
explanation of Ionic bonding properties Melting point
Melting point-Ionic compounds have high melting and boiling points =A large amount of energy is needed to separate the ions
explanation of Ionic bonding properties Hardness
Hardness-Ionic compounds are hard=The surface of the crystal is not easily scratched due to the strong ionic bond holding the ions together
explanation of Ionic bonding properties lustre
lustre-Ionic compounds do not have lustre or are not shiny=There are no free electrons moving in the structure to reflect light as they are involved in the strong electrostatic ionic bonds (unlike metals!)
explanation of Ionic bonding properties Electrical conductivity
Electrical conductivity-
Ionic compounds will not conduct electricity in the solid form=The charged particles (ions) are not able to move
Will conduct electricity when molten (or melted) =In the molten solution, oppositely charged ions are able to slide past one another and will therefore be able to conduct electricity
Will conduct electricity in an aqueous solution (dissolved in water).=When an ionic substance is dissolved in water, the ions dissociate from the lattice and can move freely to conduct an electric current. The solution is called an electrolyte
explanation of Ionic bonding properties Malleability, ductility
Malleability, ductility-Ionic compounds are brittle (not malleable or ductile)=Distortion of the crystal causes ions of like charge to come close together and the repulsion between these ions breaks or shatters the crystal
formation of ionic compounds=
metal atoms donate one or more electrons to non-metal this is called electron transfer. non metal gain metal lose