chem Flashcards
what is an element
a substance that can not be broken down chemically
whats a compound
at least 2 elements combined together in fixed proportions
how do you separate compounds into elements
by creating a chemical reaction eg to get the element copper back the oxygen needs to be chemically removed with hydrogen
what is a giant covalent molecules
many atoms joined together by covalent bonds
describe a giant covalent molecule
- they are always solid at room temperature
- they have very high melting and boiling points
what element is diamond formed from
carbon
what is graphene
a single layer of graphite. its one atom thick.
explain graphene
- good conductor of electricity
- extremely strong
what is fullerene
it is a molecule of carbon atoms with hollow shapes
explain Fullerene
- high tensile
- good conducts of heat/electricity
- used to reinforce molecules
what are the 3 states of matter
solid, liquid and gas
what are the 3 types of strong chemical bonds
metallic , covalent , ionic
what is ionic bond?
compounds formed from metals combined with non metals
what is covalent bond
compounds of non metals and in most non metallic elements
what is metallic bonds
is a compound of metallic elements and alloys
how do atoms joined together
they can join together by transferring electrons or by sharing electrons
what happens when metals and non metals transfer electrons
the atoms become charged
what are charged atoms called
ions -the metal ions are positively charged and the non metal ions are negatively charged
whats a mixture
a mix of substances
what are substances made of
mixtures, compounds or elements
explain separation of mixtures
mixtures can easily be separated because the chemicals in them are not joined together.
how are mixtures seperated
mixtures can be separated filtration , crystallisation, simple distillation , fractional distillation, chromatography
what does filtration do
its separates insoluble substances from soluble substances
what does distillation do
it separates liquids that have different boiling points
What is a an tom made up of t
It’s made up of a nucleus that is surrounded by electrons. the nucleus carries the positive charge and the electrons which surround the nucleus carry negative charge .
