Studied by 6 people
Atoms, Rates of Reaction, Reactivity of Metals, Organic 1
Why are elements different?
they contain different numbers of protons, neutrons and electrons
Proton
mass 1 charge +1
Electron
mass 0 charge -1
neutron
mass 1 charge 0
Do atoms have an overall charge?
no, they are neutral
the number of protons is equal to
number of electrons
24
Mg what is the top number and what does it mean
12
mass number and is number of protons and neutrons
24
Mg what is bottom number and what does it mean
12
atomic number and its the number of protons
1234
2888
how do you show a shell is full
put a dot next a number
What is in the nucleus of an atom?
protons and neutrons and all the mass
periods
Horizontal rows on the periodic table
groups
columns on the periodic table
how are elements arranged into periods
number of shells with electrons in
how are elements arranged into groups
number of outer shell electrons
valency
the number of bonds an atom can form
rule for valency
add atoms until all bonds are full
how to know groups valency
1234567
1234321
Dalton's Model
solid sphere 1808
Plum Pudding Model
1887-JJ Thomson- electron discovered led to ball of pos charge w/ electrons embedded in it
alpha particle scattering experiment
1905-9 plum pudding model had to change
Bohr Model
electrons orbit nucleus at set distances- shells
Proton Discovery
Rutherford-1919 - nucleus is made up of protons and neutral particles
Neutron Discovery
James Chadwick in 1932
Law of Conservation of Mass
in a chemical reaction you never lose or gain an atom
balancing equations
number of atoms on each side must be equal
Law of Constant Composition
elements combine in fixed ratios
2NH3
2 nitrogen atoms 6hydrogen atoms
NH3
1 nitrogen atom 3 hydrogen atoms
on a graph where curve is steepest it means
the reaction is fastest, most reactant particles, most collisions between reactant particles,
rate =
amount of product formed/time
Magnesium + hydrochloric acid >
Magnesium chloride + hydrogen
how do chemicals react
their molecules must collide and have have energy greater than activation energy
effect of a catalyst
decreases activation energy, percentage of successful collisions increases, rate increases
how do catalysts lower activation energy?
By providing an alternative reaction pathway
What is crude oil derived from?
Ancient biomass, mainly plankton
Mixture definition
Two plus elements not chemically combined- can be separated by physical methods
Where is crude oil found?
In rocks
Hydrocarbon
Molecules of hydrogen an carbon only
Hydrocarbons are mostly alkanes
General formula of alkanes
CnH2n+2
Methane
CH4
Ethane
C2H6
Propane
C3H8
Butane
C4H10
Combustion of carbon word equation
Hydrocarbon+ oxygen —> carbon dioxide + water
Exothermic
Energy is released
What happens in and incomplete combustion
Not enough oxygen
Hydrocarbon + oxygen—> carbon monoxide + water
how does fractional distillation work?(5 bullet points)
crude oil into tower vaporises
gases rise
tower gets colder going up
hydrocarbons condense when they reach their boiling point, big molecules further down
they are drawn off
rust (3 bullet points)
corrosion of iron.
only iron rusts
air+ water are both necessary
prevention methods (6 bullet points)
exclude oxygen and water
eg oil,
grease,
paint,
tin plate
sacrificed protection
galvanise
zinc plate excludes water/air + if scratched will react instead of the iron bc zinc is more reactive
magnesium lumps
on a ship they react and are replaced but then iron doesn’t react
how to extract metal above carbon
electrolysis of the molten compound
how to extract metal below carbon
displacement/ reduction using carbon
low grade ore
low % metal in ore
high grade ore
high % metal in ore
ores (3 bullet points)
rocks containing metal compounds
contain enough metal to make it economically viable to extract metal
ores may be concentrated before metal is extracted
reduction with iron
carbon removes oxygen from iron (carbon gains oxygen- oxidation)
Note 
Flashcard (89)