key concepts Flashcards
john d’alton model
all matter is amde from atomsthat cannot be split
thmas plum puddiing model
a postively charged dough mixed in with the negatively charged electrons in the dough
what sub atomic particledid thomas find
electrons
rutherfords nuclear model
alpha particles could bounce of atoms . the mass was found in the nucleaus and the postively charged sub atomic particles were called protons
the modern model
alectrons orbit the the nucleus
what sub atomic molecule did james chadiwick discover
the neutrons who have no charge
3 or more different elements that combine ionically end with an
ate
2 different elements that combine ionically end with an
ide
what ionic lattices
giant structures that are held together by elostractic forces (ionic bond)between the postive and negatitive ions
which diatomic molecule has a triple covalent bodn
nitrogen
what are ionic bond
the strong electrostatic froces inovlved in ionci structures
prperties of ionic compound
- high melting and boiling points
- don’t conduct electricty in a solid only in a molten
why do ionic compounds have high melting and boiling points
as to break the electrostatic forces in the ionic compounds there is more heat energy required
why can’t ionic copounds conduct electricity in a solid
when the elctrons are in a solid fixed place in a lattice they can’t move meaning charges can’t flow so can’t conduct electricty
why can ionic compounds conduct ekectricity in a liquid
when elctrons are molten (melted ) they are not in a fixed postion so they can flow and they can codnuct electricty
what a re small covalent compounds held together by
intramolecular forces which are covalent bonds
what are the properties of small covalent compounds
low melting and boiling point
liquid or gase at room tempreature
can’t conduct electricty
why do small covalent compounds have a low melting and boiling point
as there intramolecular forces are quite weak so less force is required to break the forces down to become a liquid
why can’t small covalent bodns conduct electricty
they don’t contai delocalised electrons
what is an example of a smal covalent sompound
chlroine
what are the properties of a giant covalentmolceule compound
high melting and boiling point , don’t conduct ekectricty
why do giant covalent molecules have a high meltingpoint
strong covaent bonds between them so there is a higher energy required to break those bonds
what isn’t between the giant covalent compounds
intermolecular forces
why do giant covalent compounds don’t have intermolecular forces between them
because there is only one molecule
