Transcript File - Thomas Tallis Science

Atomic structureProtons: mass 1/ charge +
Neutrons: mass 1/ charge 0
Electrons: mass 0/ charge -
Mass Number- number of
protons + neutrons in the
nucleus
Ionic bonding-atoms like to
have full outermost shells.
Here an atoms gives away or
receives an
electron to
achieve a
full shell.
The atoms attract
Because they
have a charge
(ions)
Electronic structure1st shell- up to 2 electrons
2nd shell- up to 8 electrons
3rd shell- up to 8 electrons
numerical
format of this
atom: 2,4
Non Metal + Non Metal only
Giant ionic lattice
Metal + Non- Metal only
Graphite
Atomic number- number of
protons or electrons
Carbon: 6p, 6n, 6e
Covalent bonding- here atoms
share electrons to gain a full
outermost shell.
Diamond made of Carbon atoms
Nano particles- Nanoparticles
range in size from about 100
nm down to about 1 nm.
Working with nanoparticles is
called nanotechnology. They
are useful
as
catalysts
to speed up
reactions
Group 1 elements have 1 e- on their outer
most shell
Group 2 elements have 2 e- on their
outermost shell
Etc….
Calcium’s electronic
structure
Conservation of mass- Mass is
never lost or created
Relative Atomic Mass RAMMass of each atom compared
to Carbon (12). E.g. Magnesium
has a mass of 24 (twice as
heavy as carbon)
2,8,8,2
Isotopes are atoms of an element with the
normal number of protons and electrons,
but different numbers of neutrons.
Isotopes have the same atomic number, but
different mass numbers.
Metallic bonding- Metals form
giant structures in which
electrons in the outer shells of
the metal atoms are free to
move.
Metals are good conductors of
electricity and heat, because
the free electrons carry a
charge or heat energy through
the metal
Relative Formula Mass RAFAtomic mass of each atom
added up.
Carbon = 12
Oxygen = 16
CO2 RAM= 44
How much carbon is in CO2?
CO2 RAM is 44
Carbon mass is 12
(12/44) x 100 = ? %
Answer can’t be more than
100%!
Increased temperature =
increased rate of reaction
•the reactant particles move
more quickly
•more particles have the
activation energy or greater
•the particles collide more
often, and more of the
collisions result in a reaction
•the rate of reaction increases
Increasing surface area=
increased rate of reaction
•its surface area is increased
•more particles are exposed to
the other reactant
•there is a greater chance of
the particles colliding
•the rate of reaction increases
Catalysts increase the rate
of reaction without being
used up. They do this by
lowering the activation energy
needed. With a catalyst, more
collisions result in a reaction,
so the rate of reaction
increases. Different reactions
need different catalysts.
Exothermic reactions= gives
off heat (feels hot)
Endothermic reaction= takes in
heat (feels cold)
•Increasing concentration =
increased rate of reaction
there are more reactant
particles in the same volume
•there is a greater chance of
the particles colliding
•the rate of reaction increases
Reversible reactions- you can
get back to the original
reactants
e.g. ammonium chloride
ammonia + hydrogen chloride
Electrolysis is the process by
which ionic substances are
broken down into simpler
substances using electricity.
During electrolysis, metals and
gases may form at the
electrodes
The Haber process- making
ammonia gas
Nitrogen and hydrogen will
react together under these
conditions:
•a high temperature - about
450ºC
•a high pressure - about 200
atmospheres (200 times normal
pressure)
•an iron catalyst
N2(g)
+ 3H2(g) 2NH3(g)
Splitting up NaCl2
Increasing pressure =
increased rate of reaction.
•Because there are more
reactant particles in the same
volume
•there is a greater chance of
the particles colliding
•the rate of reaction increases
Acids- substances
with a pH of 16
Neutral- substance
with a pH of 7
Alkali/ Basesubstance with a
pH of 814
NeutralisationAcid + Alkali 
Salt + Water
(Neutral)
Acid + Metal 
Salt + Hydrogen
gas
Acid + metal carbonate salt + water + carbon
dioxide