Bonding Flashcards
(14 cards)
What are three properties of ionic bonding? (and why)
- high melting point and boiling point due to strong electrostatic forces of attraction
- soluble in water as the charged ions are attracted to the polar water molecules, this breaks the lattice apart
- hard but brittle as there are strong forces of attraction but as layers slide of each other the same charges align and repel
what are three properties of metallic bonding? (and why)
- high melting point and boiling point due to strong electrostatic forces of attraction between positive ions and the “sea” of electrons
- malleable/ductile as layers can slide of eachother and still attract
- good conductors of electricity as there are free moving electrons that can carry charge
what are three properties of covalent bonding? (and why)
- low melting point and boiling point due to weak intermolecular forces
- poor electrical conductivity as there are no free moving electrons and no ions present
- poor solubility in water as there are no charged particles to attract water molecules
what is a covalent bond?
a chemical bond that involves the sharing of electrons to form electron pairs between atoms
what is the charge of an electron?
-1
what is the charge of a proton?
+1
what is the relative mass of a proton?
1
what is the relative mass of a neutron?
1
what is the relative mass of an electron?
1/1840
what are isotopes?
isotopes are atoms of the same element which have different numbers of neutrons and therefore a different mass number
what are four properties/uses of diamond?
- tetrahedral arrangement, all atoms joined together
- high melting point due to the many covalent bonds
- doesn’t conduct as there are no free electrons: all are used in the bonds
- used in cutting tools as they are very hard with very high melting points
what are four properties/uses of graphite?
- each carbon joined together 3 others forming layers of hexagons that can slide over eachother easily due to weak forces between layers
- very high as many covalent bonds need to be broken
- conducts as each carbon has one delocalised electron that is free to move within layers
- graphite is used in electrodes as it has a high melting point and can conduct
why are alloys not regarded as compounds?
alloys do not have a fixed ratio of atoms of each element
why are alloys generally tougher and stronger than pure metals?
in an alloy, different sized atoms disrupt the regular lattice and the layers cannot slide over eachother easily. the structure is harder but more brittle
