Light
Give the speed of light.
3 x 10^8 m/s
Who did Gieger and Marsden work with?
Rutherford
Give the name for the diagram used to determine the absolute magnitude and temperature (Kelvin) of a star.
Hertzsprung Russel diagram
Who produced the plum pudding of the atom.
J.J Thompson
Describe escape velocity.
The velocity required to escape a planet/bodies gravitational force.
Distinguish between ABSORPTION and EMISSION SPECTRA.
ABSORPTION SPECTRA where light has been absorbed by the atom thus you see a dip in the spectrum.
EMISSION SPECTRA atoms releasing photons at those wavelengths.
Describe Milkman's experiment.
Millikan was able to measure both the amount of electric force and magnitude of electric field on the tiny charge of an isolated oil droplet and from the data determine the magnitude of the charge
A 800 V electric field is applied to an electron that is initially at rest.
Calcualte the final speed of the electron.
½ mv2 =qv
V = 2 x (1.602 x 10^-19) x 800/ (9.109 x 10^-31)
V =
Describe the Maltese Cross Discharge Tube.
Maltese cross obstacle and fluorescing glass show that electrons in a Crookes tube travel in straight lines and are affected by magnetic fields.
Outline the difference between a Geostationary (GEO) and Low Earth Orbit (LEO) satellite.
Geostationary - orbit the Earths equator and often remains in one spot. Orbits at altitudes above 1000km.
Low Earth orbit - orbits at a low altitude
(less than 1000km)
Cathode rays travel in a _____________ line
Straight
What was the purpose of Thompsons 1897 experiment?
Thomson’s experiment was to measure the mass of the particle. It was also used to measure the charge to mass ratio of the cathode ray.
Explain the relationship between electric and magnetic fields.
Force by electric field Eq
Force by magnetic field qvB
Eq = qVB
Describe Rutherford's 1911 Experiment.
Rutherford bombarded very thin sheets of gold foil with fast moving alpha particles.
The vast majority of the alpha particles passed through the gold, he reasoned that most of the atom was empty space.
A few particles were highly deflected must have experienced a positive charge and the majority of the mass of the atom must be concentrated in a very small space in the atom's interior which he called the nucleus.
Find the ALTITUDE for a SATELLITE
M = 6 x 10^24 kg
T = 102 minutes
Earths R = 6371 km
r3 = T2 GM / 4 x (pi)
r3 = T2 GM / 4 x (pi)
r3 = (102 x 60)2 (9.8)(6 x 1024) / 4 x (3.14)
r = square 3 (102 x 60)2 (9.8)(6 x 1024) / 4 x (3.14)
Calculate the energy (in eV) of the wavelength being emitted at the 200 nm line in the hydrogen spectrum AND the colour of the light emitted at this wavelength.
E= hf = h c/wavelength
E= (6.626 x 10^-34) (3 x 10^8) / (200 x 10^-9)
E = _________/ 1.6 x 10^-19
E = __________eV
Describe Bohr's model of the atom.
In the Bohr model of the atom, electrons travel in defined circular orbits around the nucleus.
Explain why Super Giants are larger than Red Giants.
A red supergiant is a red giant but significantly bigger. They are all formed when a main sequence star is unable to convert hydrogen to helium therefore, the natural process of nuclear fusion begins fusing heavier elements causing the star to exponentially increase in size.
Outline a problem with Rutherford's model.
The model failed to show that electrons orbit the nucleus in a circular fashion.
Find the ALTITUDE for a SATELLITE
M = 6 x 10^24 kg
T = 213 minutes
Earths R = 6371 km
r3 = T2 GM / 4 x (pi)
r3 = (213 x 60)2 (9.8)(6 x 1024) / 4 x (3.14)
r = square 3 (102 x 60)2 (9.8)(6 x 1024) / 4 x (3.14)
Atoms are heated to releasing photons of light and has different coloured lines (Bright lines) which appear in the dark background in the spectrum. This is known as ______________ spectra.
Emission Spectra
Explain Chadwick's Experiment.
In 1932, the physicist James Chadwick conducted an experiment in which he bombarded Beryllium with alpha particles from the natural radioactive decay of Polonium.
Through his experiment he proved the existence of neutrons, elementary particles devoid of any electrical charge.
Describe the formation of the universe following the Big Bang.
At the instant before the Big Bang started the Universe as we know it, nothing existed – no time or matter. According to BBT energy was all that existed at this time. This energy spread out from a single point known as a singularity. The initial temperature at this single point was extremely high and as the energy spread further from the singularity the temperature began to cool. As the energy spread out and the temperature cooled energy was converted into matter. Particles that formed early on were rapidly destroyed by the high temperatures. At lower temperatures the particles became more stable and began to combine, forming atoms and molecules.
In an oil drop experiment a potential difference of 9250V was applied across the plates to stop a
4.4 x 10^-14 kg oil drop from falling. The plates are 2 cm apart. Calculate the net charge of the oil droplet.
E=V/d = 9250/2 x10^-2 = 46 2500 V/m
q= mg/E= 4.4 x10-14 x 9.8 / 46 2500
q=
1) Define escape velocity.
2) Identify factor(s) that affect escape velocity.
3) Which has a larger escape velocity. Earth or the moon
Escape velocity =the speed required to break free of an orbit is known as escape velocity.
Factors = the higher the altitude of an object above a planet the less velocity will be required to: