Describe the differences
between elements, compounds
and mixtures
ELements- Substance only
made of one type of atom
Compounds- Substance
made from more that one
type of atom.
MIxture- Substance which has
more than one type of element
but not chemically bonded
together
Describe the structure of an atom in
terms of electrons and a nucleus
containing protons and neutrons
An atom has a nucleus in middle
containing protons and neutrons
surrounded by shells containing
electrons
Describe the build-up of electrons in
‘shells’ and understand the significance
of the noble gas electronic structures
and of valence electrons.
Each atom has outer shells containing electrons. The
first outer shell of an atom is capable of containing
only 2 electrons while the other can contain up to 8
electrons. Noble gases structure is the outer shell is
filled and there is no more need for electrons for a
complete outer shell.
State the relative charges and
approximate relative masses
of protons, neutrons and
electrons
Define atomic (proton)
number and mass
(nucleon) number
Atomic number- number
of proton.
Nucleon number- number
of proton and neutron
Define isotopes
Isotopes are the atoms of the same
element which have the same number
of the proton but a different nucleon
number.