Topics I need to improve on or weak topics Flashcards
Who realised that electrons orbit in shells and were specific distances away?
Neil Bohr
What is the plum pudding model?
that the middle of an atom is positive and surrounded by negative charge
What conclusions did Rutherford draw from his alpha scattering experiment?
That an atom is mainly open space as most alpha particles passed straight through, centeral mass as some rebounded back, the nucleus is positive as some of the alpha particles (positive ions) were deflected in its path
Who first discovered electrons?
JJ Thompson
Who first said that everything is made up of particles called atoms?
John Dalton
What was fired at very thin gold
foil, which led to the nuclear
model of the atom?
Helium nuclei (alpha
particles).
These are positive ions.
What is the formula for propene?
C3H6
Do thermosetting or thermosoftening polymers melt when heated?
thermosoftening
What non metal makes up steel?
carbon
What two metal are in brass
copper and zinc
what two metals are in bronze
copper and tin
How to prevent corrosion
greasing, painting, electroplating, galvarising
How can we reduce use of worlds resources
reuse and recycle
What does LCA stand for
life cycle assesment
4 stages of process of sewage treatment
- screening 2. sedimentation 3.anaerbobic digestion of sludge 4. aerobic treatment
why is potable water not necassarily pure water?
contains dissolved substances
name a sterilising agent for sterilising potable water
chlorine, ozone, UV light
What pollutant causes acid rain?
sulfuric/nitric acid
What two things reduced the amount of carbon dioxide in the earths early atmosphere?
photosynthisis, formation o sedimentary rocks and fossil fuels
What happens to the reactivity of elements in the halogens as they get further down?
The reactivity decreases
What state is flourine at room temp
gas
What state is bromine at room temp
liquid
What state is iodine at room temp
solid
Why are group 1 called alkali metals
Because they react with water to form alkalis
why do ions with a 1+ charge and a -1 charge form a bond
electrostatic attraction between oppisitely charged ions
define giant ionic lattice
a 3d network of ions
why do ionic substances conduct electricity when molten or dissolved in water
ions are free to move
define an aqueous soloution
something dissolved in water
What is the 3 main acids
hydrochloric nitric and sulfuric
What is the formula for sulfuric acid
HSO
What is the formula for nitric acid
HNO
What ions does HCl form in a solution
H and Cl
What ions does HSO form in a solution
H2 and SO2
What ions does HNO form in a solution
H and NO
How to measure pH
indicator or a pH probe
What is a base
a metal oxide hydroxide or carbonate that reacts with an acid
what is a salt
a compound when some or all of the hydrogen is replaced by a metal
what are the products of a metal oxide and an acid
salt and water
products of metal carbonate and an acid
salt and water and carbon dioxide
How can metals be placed in order of their reactivity
add the metals to water or acid see which ones react the most on how much fizzing there is for example
Why can gold and silver be found naturally in the earths crust
its very unreactive
Define an ore
a material containing enough metal for it to be worthwhile to extract the metal from it
for the extraction of metals when is electrolysis needed
when the metal is more reactive than carbon
Why is aluminium oxide mixed with cryolite when extracting aluminium?
to lower the melting point
Why does the anode need to be replaced in the electrolysis of aluminium oxide
because the oxygen reacts with the carbon to produce co2
What is produced at the cathode in electrolysis of solutions
the metal is produced at the cathode if it is less reactive than hydrogen
What is produced at the anode in electrolysis of solutions
either a halogen or oxygen if halogen is not present
Give two examples of endothermic
reactions.
Thermal decomposition reactions, citric acid and
sodium hydrogencarbonate.
State two uses of exothermic reactions
hand warmers and self heating cans
State two uses of endothermic reactions
sports injury cool pack
What is a reaction profile?
A diagram to see wether the reactants in a reaction have more or less energy than the products
Is breaking bonds endothermic or
exothermic?
endothermic because energy is needed as bonds are strong
How do we work out the overall energy
change of a reaction?
difference between energy needed to break all the bonds of the reactants and energy released to form all the bonds in the products
