Science - All Topics Flashcards
What is the definition of the rate or reaction
How fast reactants are turned into products
How to find the rate of reaction
Quantity of reactants used or products made/time(sec)
What factors affect the Ror
Catalysts,Temperature,pressure,concentration and surface area
In terms of collision theory, how does temperature affect the Ror
Its gives the particles of the reactants kinetic energy which increases the particle’s speed. This allows for a higher chance of particles colliding resulting in a reaction.
In terms of collision theory,how does a catalyst affect the Ror
It provides an alternate low energy pathway while not being used up
In terms of colllision theory,how does concentration affect the Ror
It groups the particles closer together reducing the amount of space they can move leading to a higher chance of collision
In terms of collision theory,how does surface area affect the Ror
When the surface area is increased , the mass of the reactant is split into more pieces. This gives it a higher chance of Ror as there is more space for reactants to collide and react.
What is a catalyst
It provides a low energy pathway while lowering the activation energy of the reaction. It is also not used up during this process
What is the activation energy of a reaction
The minimal amount of energy particles need to create a successful reaction
What must there be for a chemical reaction to occur
Particles with sufficient(activation) energy,reactant particles must collide at the right angle
A collision that produces a reaction is…
A fruitful or successful collision
How does increasing the surface area affect the rate of reaction?
It increases as a result of more reactant particles exposed, leading to more frequent collisions
What unit is used for rate of reaction involving a change in mass?
g/s
What unit is used for rate of reaction involving a change in volume?
cm3/s
‘The geocentric model suggests our earth was at the centre of the Solar System’
True or False?
False
The model suggests the earth was at the centre of our universe
‘The heliocentric model suggests our earth was at the centre of the Universe’
True or False?
False
The model suggests our sun is at the centre of the solar system
Who supported the geocentric model?
Ptolemy (Google) and Aristotle
What was the major flaw in the geocentric model?
It couldn’t properly explain retrograde motion
Who suggested the heliocentric model?
Nicolaus copernicus
Who pioneered the telescope?
Galileo
Who suggested the planets moved in elipses and when?
How did this disprove the last models?
Johannes Kepler in 1600AD
The models prior to this suggested the planets moved in circles
The gravitational pull of the sun results in the planets orbits being eliptical
What Life cycles of stars are the same size as our sun
- Protostar
- Main Sequence Star
- Red giant
- White dwarf
- Black dwarf
Life cycle of a star much bigger than our sun
- Protostar
- Main sequence star
- Red supergiant
- Supernova
- Neutron star or blackhole
What force causes obects in space to orbit each lther(e.g the planets orbit the sun)
Gravitational pull
Who discovered infra red radiation
William hershall
What did people back then use to answer the unkown
Religion
Who and when documented the first astronmocial observance
1000bce the babylonians
Who figured out that the milky way was not the only galaxy and when
Edwin hubble did in the 1920s
What does hubble’s law theorize
The universe is constantly expanding and is getting faster and faster
What are the different types pf galaxies
Spiral,irregular and ellipitical
What is dark matter
Invisible matter that does not react to electromagnetic forces
When is it believed that the solar system was formed
4.6 billion years ago
How was the solar system formed
A large supernova occured woth its effect travelling in waves. A solar nebula was formed along witha large cloud of dustcand gas which formed stars and moons
How was our sun formed
The gas (hydrogen)nwhich was at the center of the nebula that occured has collapsed cuasing the creation of the sun
When is it believed that the earth was formed after the big bang
9 billion years after the universe was formed
What can the big bang be described as
The point where space and time started to exapnd beyong something smaller than an atom
In terms of waves, if an object is moving away from us what happens to the light’s wavelength.
It is gets longer and if the object is moving towards us it gets shorter.
What do all luminous objects emit
Waves with wavelengths
What is the definiton of a wave length
The distance between two identical points on a successive wave
The wavelength of blue light is shorter than red light
Yes
What is light recieved on earth from a galaxy said to be
Red shifted
What are some evidence for the age of the big bang
CMBR,red shift
What forces keep a satellite in orbit
Velocity(straight course) and gravitational pull(so it doesn’t fly off to the next kown universe)
How does a satellite get put into orbit
By a rocket
What are the types of satellite
Geostationary,Polar and low eart orbit
What does it mean if something is in a geostationary orbit
It is always in one spot above the equator
What does it meam if something is in a low earth orbit
It is 1000 km from the earth
What does something in a polar orbit go over
The north and south pole
How long does it take for a geostationary staellite to make a full orbit
One day
How long does it take for a low plar orbit to orbit once
90 minutes
How long does it take for a low earth orbit to orbit once
90 minutes
What orbits stay above the same point all the time
Geostationary and low polar orbit
Not LEO
What are the 2 types of telescope
Refracting and reflecting
How does a refracting telescope work
Bends light through a lens to form an image
What are the disadvantages of a refracting telescope
Some light is reflected off the lens leading to afaint image
Large leneses asre needed to inprove magnification
Life cycle of stars with low mass: detailed (kinda) ඩ
-The cloud of gas and dust heats as it contracts. When it’s hot but hasn’t started nuclear fusion, it’s known as a protostar and this stage can last for around 100000 years
-Stars are formed from the cloud and collapse under their own gravity and can begin nuclear fusion.
-When it starts fusion, the star will shine and the outward pressure will stabilise the star’s gravity, now know as a ‘Main Sequence Star’
-Core of star heats as contracts until hydrogen fusion begins
-The star will then exhaust it’s hydrogen and will begin fusing helium and swells out, end of Main Sequence. Helium keeps fusing until hot enough to fuse into oxygen and carbon.
Continued star stages: smol
-same size or smaller than our sun swell and become red giant
-when fusion srops radiation is released and star collapses onself becoming a white dwarf, the cools down and becomes black dwarf
How to operate a nuclear power station
Control rods with uranium or plutonium create heat, transferred to water to make it steam. Radioactive heated water to power different water system, linked to a turbine which produces electricity. Converted back to water in condenser to go back into reactor vessel for another cycle
How to operate coal-fired power station
Coal burned in boiler to heat water to become steam, drives turbine which converted into electricity theough generator, steam cooled back to water ready for another cycle
What are the different energy resources
Biofuels,nuclear power,fossil fuels,geothermal,solar,tidal and wind
How does biofuel produce energy
Chemical energy stored in once alive things are transferred into thermal energy which boils the water
How is most energy(electricity) made and related
Thermal energy is made which boils water into steam that turns a generator. This turns kinetic energy into electricity
How does nuclear power create energy
Atoms in radioactive fuels are split into two which causes a chain reaction. When they split they create enegy which boiils watr
How do fosil fuels produce energy
Thwy are burned tansferring chenical energy into thermal which boils wter( greenhouse gaes are also emitted when brned)
How does geothermal energy produce electricity
Use the earth’s natural heat caused from hot rocks which boils water that is Fed underground . This turns into steam
How does solar energy create power
Energy from the sun iis used to heat solar panels which is made into electricity by the panel or cells(very low energy made)
How does tidal power create electricity
High tide is trapped and released as a low tide. When released,turbines are spun which creates energy
How does wind energy create electricity
The force of the wind causes the blades to spin which transforms kinetic energy to electricity
