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Atomic Theory - INS, KEY - Coggle Diagram
Atomic Theory - INS
scientific models
Continuum model
early BCE
ancient Greeks
all matter made out of
fire, earth, water, air
basis of model
could be broken down into smaller pieces
solid-ball model
160-370BCE
Democritus
matter was not continous
made up of
tiny, solid, unbreakable particles
'atmos'
indivisible
plum pudding model
1904
J. J. Thompson
atom is round ball
of positive charge
with negative charged electrons embedded in it
dynamide model
1904
Philipp Lenard
atoms as mostly empty spaces
filled with fast-moving dynamides
neutrally charged particles
made up of heavy positively particle
nuclear model
1911
Ernest Rutherford
fired a beam of positively charged alpha particles at gold foil
most alpha particles went through foil
small number were deflected
lead to development of nuclear model
most mass on positively charged nucleus
surrounded by space of negative electrons
planetary model
1913
Niels Bohr
electrons can only travel along certain pathways around nucleus
explained why
different elements produce different colour light when heated
electrons moving from higher to lower orbits
planetary models with neutrons
1932
James Chadwick
discovered neutrons
nucleus
cluster of positively charged protons
charge-neutral neutrons
electron cloud model
1932-today
position of electron can never be know exactly
impossible for electrons to orbit around nucleus
electrons form cloud
scientists can predict the shape of these clouds
First hand investigation
burning a candle in closed container
combustion reaction
fuel + oxygen
products + energy
parafin wax
phlogiston
long-standing assumption
materials that burn contain phlogiston
responsible for making it burn
what scientific investigation
qualitative observations
flame extinguished
increase water level
change in pressure
quantitative observations
time to extinguish
height of water level
characteristics of acids and bases
qualitative
acid base indicator
change in colour
match with chart
determine pH
universal
quantitative
pH meter
more accurate
pH scale
ranges from 0-14
pH 0-6 acids
corrosive
H ions (hydrogen)
pH 8-14 bases
caustic
OH ions (hydroxide)
7 neutral
reflects the concentration of hydrogen ions
Reactions with carbonate
carbonate with acid
Observing Patterns
elements and their properties
metals
good conductors
malleable(bent)
lustre (shiny)
ductile (streched into wire)
usually solid at room temperature
high melting point
non-metals
dull
poor conductors
insulator
brittle
not always solids
Dmitri Mendeleev (1834-1907)
grouping elements
left gaps
reactivity
with similar properties in columns
drafted first periodic table
peer review and collabration
unstable isotopes
radioisotopes
carbon
carbon-14
8 neutrons (neutral)
6 protons (+)
carbon-12
6 neutrons
6 protons
element with unstable nucleus
radioactive decay
to become stable
nuclear radiation
half-life
1/2 time taken for a radioisotope to decay
irregular pattern
negative exponential
difficult to identify pattern
long half life
carbon-14 has half life of 5730 years
KEY
Module 3
Module 2
Module 4
Module 1