Bonding Flashcards
Why do ionic compounds have a high melting point?
The bonding is between two oppositely charged ions, this causes strong electrostatic forces, this means a large amount of energy is required to overcome the bonds.
What is covalent bonding?
Bonding that involves the sharing of electrons between two non-metals forming a covalent compound that is insoluble in water.
What is electronegativity?
This is power/ability of an atom to attract a lone pair of electrons in a covalent bond.
What is bond polarity?
Polarity is about the unequal sharing of electrons in a covalent bonds. A bond is considered polar when there is a great difference in electronegativity between the two atoms. (F,O,N,Cl,Br )
What is metallic bonding?
This occurs between two metals, it consists of a lattice of positive ions surrounded by a sea of delocalised electrons.
Describe and explain the properties of metallic bonding.
Metals can conduct electricity as there as delocalised electrons free to carry the charge through the structure.
Metals are malleable and ductile as the metal ions are arranged into layers which can Slide Over each other.
They have a high melting point as it requires high energy to overcome strong electrostatic forces between positive metal ions and delocalised electrons.
What is a Dipole-dipole force?
Acts between molecules that have a permanent dipole. This is when one atom in a bond is more electronegative that the other so the electrons are pulled towards it ie, HCl, chlorine has a much greater electronegativity than hydrogen so it pulls the electrons towards it causing it to have a delta negative charge.
What is hydrogen bonding?
This only occurs when a hydrogen atom is bonded to an electronegative atom , this will produce a strong enough partial charge. Another electronegative atom with a lone pair of electrons of another molecule will be attracted to the slightly positive hydrogen, which causes the formation of a hydrogen bond, ie .H2O
What are Van der Waals?
This type of intermolecular force exists in every atom, these charges produce very weak electrostatic attractions, they are the weakest type of intermolecular force but a great number of them will increase the boiling point.
Why is water more dense than ice?
In liquid state, the hydrogen bonds in water breaks and reform easily as the molecules are moving around. When water freezes the molecules are no longer free to move around and are held in a fixed position, meaning molecules are packed more tightly so water is more dense than ice.
