Transcript File - Mr. Standifer`s World of Science

Final Review
149-170
Ecology
149-158
Question 149
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With Warmer temps disease carrying
insects migrate north, bringing plague and
disease with them.
With warmer oceans we will get more
frequent and stronger hurricanes.
Some areas will see more flooding due to
increased rain other areas will suffer
serious droughts and heat waves. Africa
will receive the worst of it, with more
severe droughts also expected in Europe.
The water in the oceans will expand in
volume (warm things expand), and
additional water enters them which had
previously been locked up on land in
glaciers raising sea level and flooding
some of our most populated cities along
the coasts.
Forest Fires, Crops, water supplies,
extinctions, the list goes on. 
Question 150
Yellow= minor risk
Orange = moderate risk
Red = High risk
Notice Wake County’s risk level
– Radon-222 is a colorless,
odorless, and tasteless
naturally occurring gas
produced by the radioactive
decay of uranium-238.
– Outdoors, radon gas seeps
from the ground into the
atmosphere, where it is
diluted to harmless levels.
– Radon gas can enter through
cracks in a foundation and
build up to high levels indoors.
– Once indoors, radon gas
decays into radioactive
elements that can be inhaled,
causing an increased risk of
lung cancer.
Question 151
• Acid precipitation is
precipitation with a pH
of less
than 5.0.
• Acid precipitation forms
when sulfur dioxide and
nitrogen oxides
combine with
atmospheric moisture
to create sulfuric acid
and nitric acid.
Question 152
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– The ozone layer serves as
a protective shield as it
absorbs and filters out
harmful UV radiation.
The ozone layer serves as a protective
shield as it absorbs and filters out harmful – Chlorofluorocarbons
(CFCs), which were
UV radiation.
previously used in
The Montreal Proetocol, which 186
countries had signd by 2003, calls for a
refrigerators, cleaning
phase-out in the production and use of
agents, and as propellants
most ozone-destroying chemicals by
in aerosol cans, used to
developed countries by the year 2005 and
developing countries by the year 2015.
contribute to ozone
destruction in the upper
atmosphere.
Question 153
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Cl + O3 ==> ClO + O2
ClO + O ==> Cl + O2
-----------------net result: O3 + O ===> 2O2
Chlorofluorocarbons (CFCs), which
were previously used in refrigerators,
cleaning agents, and as propellants in
aerosol cans, used to contribute to
ozone destruction in the upper
atmosphere.
The chlorine atoms of the CFCs act as
a catalyst where they attach and
remove an Oxygen atom from the
Ozone molecule (remember Ozone is
O3) turning it back into regular
Oxygen.
That Chlorine can continue the
process over and over and is not used
up in the chemical process so a single
CFC molecule can destroy 100,000
ozone molecules before it is removed
from the stratosphere.
Question 154
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Simply put, biodiversity is life in all its
variety: over 14 million species found
from mountain top to deep-sea vent.
But it is much more. Those species
connect, and interact. Those
interactions create communities and
systems, and those systems provide
goods and services such as oxygen
production, pollination, water
filtration and storage, pest control,
food production, carbon storage and
erosion control.
Again, simply put, biodiversity
anchors nature’s life support system.
The effect of human activities magnified in recent years by
population growth and global climate
change - has greatly reduced
biodiversity (mostly through habitat
destruction) in ecosystems around
the world.
Question 155
• Biotic factors ; are living
components of an
ecosphere.
• Abiotic factors; are nonliving components of an
ecosphere such as
minerals and nutrients,
sunlight, temperatures,
precipitation, etc….
Question 156
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The early period of hunters and gatherers less than a few million people
The rise of agriculture - first major increase
in the human population (still not large yet
though)
The Industrial Revolution - improvements in
the food supply and health care led to a
rapid population growth
The human population has skyrocketed in
recent times. 2000 years ago, the Earth was
home to just 300 million humans, roughly
the population of the United States today.
Two hundred years ago, 1 billion humans
lived on our planet Earth. The world
population is now right at 7 billion and
growing rapidly. If current trends continue,
we will add another 1 billion to the world
population every 13 or 14 years.
This explosive growth came about because
death rates fell faster than birth rates. The
availability of antibiotics, immunizations,
clean water, and increased food production
yielded tremendous improvements in infant
and child mortality. A rise in average life
expectancy has also contributed to the surge
in human numbers.
Question 157
• The 7 billion
(6,973,738,433 )
currently on Earth could
probably not all live like
Americans, much as
they might want to.
Question 158
Astronomy Review
159-170
Question 159
– Earth’s atmosphere
blocks infrared radiation,
ultraviolet radiation, X
rays, and gamma rays. So
we loss all that
information with ground
telescopes.
– When Earth’s atmosphere
does allow certain
wavelengths to pass
through, the images are
blurred.
Hubble added clarity to the discovery of the
brown dwarf star GL229B. The brown dwarf was
about the size of Jupiter, and thanks to Hubble’s
Wide Field Planetary Camera-2, astronomers
were able to calculate the star’s size and
distance from Earth.
Question 160
The autumnal equinox occurs
around September 21, halfway
between the summer and the
winter solstices when the Sun
is directly over the equator.
This is when the Sun is directly
overhead at the equator, both
hemispheres receive equal
amounts of sunlight.
Question 160 continued
Question 161
As a result of the tilt of Earth’s axis and Earth’s
motion around the Sun, the Sun is at a
higher altitude in the sky during summer
than in the winter.
Altitude is measured in degrees from the
observer’s horizon to the object. There
are 90 degrees from the horizon to the
point directly overhead, called the zenith
of the observer.
As Earth moves from position 1, through
position 2, to position 3, the altitude of
the Sun decreases in the northern
hemisphere.
Question 162
Earth's rotation is the rotation of the solid
Earth around its own axis. Creates day and
night and takes one full day to rotate
completely.
The Earth rotations from East to West
Question 163
– When the Moon perfectly blocks
A solar eclipse occurs when
the Sun’s disk, we see only the
the Moon passes directly
dim, outer gaseous layers of the
between the Sun and Earth
Sun in what is called a total solar
and blocks our view of the
eclipse.
Sun.
– A partial solar eclipse is seen
when the Moon blocks only a
portion of the Sun’s disk.
– Notice for a Total eclipse to take
place you must be in the Umbra
(shadow) of the moon.
Question 164
• A lunar eclipse can happen only
at the time of a full moon, when
the Moon is in the opposite
direction from the Sun.
• A total lunar eclipse occurs
when the entire Moon is within
Earth’s umbra.
• A lunar eclipse occurs when
the full Moon passes
through Earth’s shadow.
Question 165
All planets are in an
elliptical orbit that is
not at a constant
distance from the Sun.
Perihelion is when a
planet is at the closest
point to the Sun in its
orbit.
Aphelion is when a planet
is farthest point from
the Sun during its orbit.
Question 166
• Kepler’s second law states
that a planet moves fastest
when close to the Sun and
slowest when far from the
Sun. Each shaded area
below is equal to the same
amount of time.
Question 167
Ancient astronomers assumed that the Sun,
planets, and stars orbited a stationary Earth
in what is now known as a geocentric model,
meaning “Earth centered.”
Some aspects of planetary motion were difficult
to explain with a geocentric model.
– The normal direction of motion for all
planets, as observed from Earth, is toward
the east.
– Retrograde motion is when a planet
occasionally will move toward the west
across the sky.
In 1543, Polish scientist Nicolaus Copernicus
suggested that the Sun was the center of the
solar system.
– In a Sun-centered, or heliocentric, model, the
inner planets move faster in their orbits than
the outer
planets do.
– As Earth bypasses a slower-moving outer
planet, it appears that the outer planet
temporarily moves backward in the sky.
Question 168
What is this change in wavelength
called? Doppler Effect
Spectral lines (light coming from
stars) are shifted in
wavelength by motion
between the source of light
and the observer due to the
Doppler effect.
• If a star is moving toward
the observer, the spectral
lines are shifted toward
shorter wavelengths, or
blueshifted.
• If the star is moving away,
the wavelengths become
longer, or redshifted.
Question 169
A spectrum is just a fancy term for the different
colors of light that are coming from a star.
If you've ever shined light through a prism and
seen the rainbow of colors that comes out
the other end, that’s a spectrum.
The light that comes to us from stars is very
similar - although it looks to our eyes like it is
just one color, it is actually made up of many
different colors.
The spectra that we see coming from stars often
contain what look like dark lines at particular
colors, which means there is much less light
coming from the star at that color than at the
nearby colors. This usually means that the
star's atmosphere contains certain types of
molecules which absorb light of that color, so
we don't see as much of it coming from the
star. Astronomers can use the information
from these "spectral lines" to figure out what
chemical composition that star is made of.
Question 170
• A nebula (pl. nebulae) is a
cloud of interstellar gas
and dust.
– Star formation begins when
the nebula collapses on
itself as a result of its own
gravity.
– As the cloud contracts, its
rotation forces it into a
disk shape.
– A protostar is a hot
condensed object that
forms at the center of the
disk that will become a new
star.