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atoms ions molecules, relative mass, relative charge - Coggle Diagram
atoms ions molecules
atoms
The smallest particles of an element
consist of a nucleus
contains protons and neutrons
electrons move around the nucleus at high speeds
known as the electron shells
properties of sub-atomic particles
proton
1
+1
proton and mass number
diff elements have diff number of protons
the number of proton in their atoms is called the proton number/atomic number
elements r arranged in the periodic table
according to their proton number
neutron
1
0
electron
1/1840
-1
responsible for the chemical properties of elements
number of protons and electrons r the same
therefore an atom is electrically neutral
the mass of an atom
contributed by the proton and neutrons only
bc the mass of electrons r negligible
the sum of the protons and neutrons in the nucleus
is called the mass number or the nucleon number
atoms of different elements differ in size and mass
due to different number of
proton
neutron
electron
threats of atomic bombs
when a neutron hits an atom of uranium
nucleus splits
the splitting release a large amount of nuclear energy and also more neutrons
as more neutrons r being released
they can hit more uranium atoms to release more nuclear energy and neutrons
resulting in a chain
of splitting atoms takes place from a single neutron
only the atoms of elements
which can sustain a chain of reaction
of the splitting of atoms
can be used to make bombs
besides uranium
the other element
called plutonium
is also used to make atomic bombs
electronic structure of an atom
in an atom
electrons are arranged in electron shells around the nucleus
electrons must first fill the lowest energy shell completely
before filling the next shell
for each energy level
there is a maximum number of electrons that is allowed to occupy
the electronic structure
is the arrangement of electrons in an atom
The outermost shell/valence shell
is the electrons shell which is the furthest from the nucleus
the electrons in that shell
are called the outermost electrons/valance electrons
stable electronic structures of noble gases
when an atoms has the max number of electrons in the outermost shell
it is stable and unreactive
the atom is said to have stable electronic structure
stable noble gas electronic structure
an atom with a max of 2 electrons at n=1
has a duplet structure
only helium has a duplet structure
an atom with a max of 8 electrons at n=2
has an octet electronic structure
neon has an octet electronic structure
an atom with a max 8 electrons at n=3
has an octet electronic structure
argon has an octet electronic structure
all elements in group O of the periodic table have stable electronic structures
they are called noble gases
they are inert and exist as monatomic elements
when atoms do not have a max number of electrons in the outermost shell
they are said to not have a stable electronic structure
some atoms will lose electrons and others will gain electrons
so that they can have a max number of electrons at the outermost shell
to achieve a stable electronic structure
in this case
atoms will change into ions
relative mass
relative charge