Download Ch. 28 Test Topics

Science 9 Test Topics:
Ch. 28
-Define the Universe.
-Know how to read numbers in scientific notation.
-Know what a light year is.
-Light travels 3 x 108 m/s
-186,000 miles per second
-671 million miles per hour
-A light year is distance light can travel in a year.
-9.5 x 1012 km
-about 6 trillion miles
-Know what an Astronomical Unit (AU) is.
-Distance from Earth to Sun
-1.5 x 108 km = 1 AU
-Know the closest galaxy similar in size (Andromeda; 2.5 million ly) and
closest star to our Sun (Proxima Centauri; 4.2 ly)
-Know the relationship between light year and the time it takes light to reach us here on Earth (for
example if star is 5 light years away, how long does it take light to get here)
-Know the different tools that scientists use to study space
-telescopes
-Galileo was the first to use a telescope
- refracting (uses lens)
-reflecting (uses mirrors)
-radio
-infrared
-x-ray
-spectroscopy
-use spectrometer to split light into spectrum and each
element and compound has different spectral line
pattern
-artificial sattelites
-Hubble telescope (launched 1990)
-Space Probes (ex. Voyager 1 and 2)
-Mars Rovers
-Space Shuttles
-Know the basics of the Electromagnetic Spectrum
-Know the difference between natural and artificial satellites
-Be able to describe our galaxy, the Milky Way.
-spiral galaxy
-100,000 ly across
-2,000-3,000 ly thick
-Sun is 26,000 ly from center of Milky Way
-looks like flattened disk with central bulge
-Define what a galaxy is and know the different shapes
-Spiral
-barred spiral
-eliptical
-lenticular
-irregular
-Know what the central black hole theory is.
-Define escape velocity and know what the escape velocity is for a black hole.
-Know that the distances between stars are 10,000 times greater than the distances between planets.
-Know that the distances between galaxies are a million times greater than the distances between stars.
-Know what Doppler Shift is and how the Doppler shift depends on distance between listener and object
making sound. Doppler shift is related to the net change between the source of the waves and the
observer.
- Know what redshift and blueshift is and when it happens.
-Know that the faster the source of light is moving the greater the shift of light.
-Know that Edwin Hubble discovered that the farther away a galaxy was, the faster it was moving away
from Earth.
-Know the universe is continually expanding and how we know this.
-Be able to describe the Big Bang theory says the universe began as a huge explosion between 10 billion
and 20 billion years ago.
-Know that all matter and energy started in a space smaller than the nucleus of an atom and that this
space is called a singularity.
-Know what evidence we have to support the Big Bang theory.
-expanding universe
-cosmic background microwave radiation
-the proportion of hydrogen to helium and other elements
-current temperature of universe
-Know that the most abundant element in the universe is Hydrogen (91.9%), the second is Helium (8 %).
All other elements include 0.1% of the universe.
-Define planetary system.
-Be able to describe how our solar system was formed from a nebula (this is known as the
nebular theory)
-Define binary star system.
-Know that this is the order of objects in the universe from smallest to largest:
planet, solar system, star, star cluster, galaxy, galaxy cluster, super cluster
-Know a local group of galaxies are galaxies that are in the close by each other and in our galaxy
cluster. The other galaxies in our local group that we viewed in class were Large Magellanic Cloud,
Small Magellanic Cloud, Sagittarius, Andromeda
-When Andromeda is viewed it has a blue shift, which means it is moving towards the Milky Way. They
are predicted to collide and merge in about 4 billion years.